Image processing device and method, and recording medium

Claim 2

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; and binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; gamma correction means for carrying out gamma correction of the multivalued image data after shifting up the brightness; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 3

The image processing apparatus as claimed in claim 1 , wherein said multivalued image processor further comprises black-down means for changing a level of pixels, which are present in a level equal to or less than a relative maximum near the minimum value of the multivalued image data after increasing the contrast by said contrast-up means, into the minimum value.

Claim 4

The image processing apparatus as claimed in claim 2 , wherein said multivalued image processor further comprises a spatial frequency filtering processor for carrying out spatial frequency filtering processing of the multivalued image data passing through the level change by said black-down means.

Claim 5

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; and binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; first contrast-up means for increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; gamma correction means for carrying out gamma correction of the multivalued image data after level change by said first contrast-up means; and second contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 6

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; and binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; first contrast-up means for increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; gamma correction means for carrying out gamma correction of the multivalued image data after level change by said first contrast-up means; and second contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 7

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; and binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; wherein said multivalued image processor comprises: level changing means for adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; gamma correction means for carrying out gamma correction of the multivalued image data after the addition by said level changing means; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 8

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; and binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; wherein said multivalued image processor comprises: level changing means for adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; gamma correction means for carrying out gamma correction of the multivalued image data after the addition by said level changing means; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 9

The image processing apparatus as claimed in claim 5 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 10

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; second gamma correction means for carrying out gamma correction of the multivalued image data after shifting up the brightness; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 11

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; second gamma correction means for carrying out gamma correction of the multivalued image data after shifting up the brightness; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 12

The image processing apparatus as claimed in claim 7 , wherein said multivalued image processor further comprises black-down means for changing a level of pixels, which are present in a level equal to or less than a relative maximum near a minimum value of the multivalued image data after increasing the contrast by said contrast-up means, into the minimum value.

Claim 13

The image processing apparatus as claimed in claim 8 , wherein said multivalued image processor further comprises a spatial frequency filtering processor for carrying out spatial frequency filtering processing of the multivalued image data passing through the level change by said black-down means.

Claim 14

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; first contrast-up means for increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; second gamma correction means for carrying out gamma correction of the multivalued image data after level change by said first contrast-up means; and second contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 15

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: brightness-up means for shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; first contrast-up means for increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; second gamma correction means for carrying out gamma correction of the multivalued image data after level change by said first contrast-up means; and second contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 16

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: level changing means for adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of another level; second gamma correction means for carrying out gamma correction of the multivalued image data after the addition by said level changing means; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 17

An image processing apparatus comprising: a histogram generator for generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processor for processing the multivalued image data using the histogram generated by said histogram generator; binarization means for converting the multivalued image data which are processed by said multivalued image processor, into binary image data representing pseudo-gray levels; multivalue means for converting binary image data output from said binarization means into multivalued data to be displayed, and for outputting the multivalued data to be displayed; first gamma correction means for carrying out gamma correction of the multivalued data output from said multivalue means; and a display unit for displaying a multivalued image in response to the multivalued data passing through the gamma correction by said first gamma correction means; wherein said multivalued image processor comprises: level changing means for adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of another level; second gamma correction means for carrying out gamma correction of the multivalued image data after the addition by said level changing means; and contrast-up means for increasing contrast of the multivalued image data by changing a level of at least part of the pixels after gamma-corrected by the second gamma correction means into another level.

Claim 18

The image processing apparatus as claimed in claim 11 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 19

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 20

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 21

The image processing method as claimed in claim 13 , wherein said multivalued image processing step further comprises a black-down step of changing a level of pixels, which are present in a level equal to or less than a relative maximum near the minimum value of the multivalued image data after increasing the contrast, into the minimum value.

Claim 22

The image processing method as claimed in claim 14 , wherein said multivalued image processing step further carries out a spatial frequency filtering processing of the multivalued image data passing through the level change by the black-down.

Claim 23

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 24

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 25

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 26

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 27

The image processing method as claimed in claim 17 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 28

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a second gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 29

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a second gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 30

The image processing method as claimed in claim 19 , wherein said multivalued image processing step further comprises a black-down step of changing a level of pixels, which are present in a level equal to or less than a relative maximum near the minimum value of the multivalued image data after increasing the contrast, into the minimum value.

Claim 31

The image processing method as claimed in claim 20 , wherein said multivalued image processing step further carries out a spatial frequency filtering processing of the multivalued image data passing through the level change by the black-down.

Claim 32

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a second gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 33

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a second gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 34

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a second gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 35

An image processing method comprising: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a second gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 36

The image processing method as claimed in claim 23 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 37

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 38

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the gamma correction into another level.

Claim 39

The recording medium having computer readable image processing program code means as claimed in claim 25 , wherein said multivalued image processing step further comprises a black-down step of changing a level of pixels, which are present in a level equal to or less than a relative maximum near the minimum value of the multivalued image data after increasing the contrast, into the minimum value.

Claim 40

The recording medium having computer readable image processing program code means as claimed in claim 26 , wherein said multivalued image processing step further carries out a spatial frequency filtering processing of the multivalued image data passing through the level change by the black-down.

Claim 41

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels of the entire pixels after the gamma correction into another level.

Claim 42

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels of the entire pixels after the gamma correction into another level.

Claim 43

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels of the entire pixels after the gamma correction into another level.

Claim 44

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; and a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels of the entire pixels after the gamma correction into another level.

Claim 45

The recording medium having computer readable image processing program code means as claimed in claim 29 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 46

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a second gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 47

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a second gamma correction step of carrying out gamma correction of the multivalued image data after shifting up the brightness; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 48

The recording medium having computer readable image processing program code means as claimed in claim 31 , wherein said multivalued image processing step further comprises a black-down step of changing a level of pixels, which are present in a level equal to or less than a relative maximum near the minimum value of the multivalued image data after increasing the contrast, into the minimum value.

Claim 49

The recording medium having computer readable image processing program code means as claimed in claim 32 , wherein said multivalued image processing step further carries out a spatial frequency filtering processing of the multivalued image data passing through the level change by the black-down.

Claim 50

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a second gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 51

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a brightness-up step of shifting up entire pixel levels of the multivalued image data except for a pixel level with a maximum value; a first contrast-up step of increasing contrast of the multivalued image data by changing into another level a level of at least part of the pixels after the shift-up; a second gamma correction step of carrying out gamma correction of the multivalued image data after level change by the first contrast-up; and a second contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 52

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a second gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 53

A recording medium having computer readable image processing program code means for causing a computer to process image data, said image processing program code means causing the computer to execute: a histogram generating step of generating a histogram by dividing pixels constituting multivalued image data into levels; a multivalued image processing step of processing the multivalued image data using the histogram generated by said histogram generating; a binarization step of converting the multivalued image data which are processed by said multivalued image processing, into binary image data representing pseudo-gray levels; a multivalue step of converting binary image data obtained by said binarization into multivalued data to be displayed, and of outputting the multivalued data to be displayed; a first gamma correction step of carrying out gamma correction of the multivalued data obtained by the multivalue converting; and a display step of displaying a multivalued image in response to the multivalued data passing through the first gamma correction step; wherein said multivalued image processing step comprises: a level changing step of adding pixels near a maximum value and a minimum value of entire pixels of the multivalued image data to pixels of other levels; a second gamma correction step of carrying out gamma correction of the multivalued image data after the addition by the level changing; and a contrast-up step of increasing contrast of the multivalued image data by changing a level of at least part of the pixels after the second gamma correction step into another level.

Claim 54

The recording medium having computer readable image processing program code means as claimed in claim 35 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 55

The image processing apparatus as claimed in any one of claims 1 , 2 and 3 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 56

The image processing apparatus as claimed in claim 4 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 57

The image processing apparatus as claimed in any one of claims 7 , 8 and 9 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 58

The image processing apparatus as claimed in claim 10 , wherein said multivalued image processor further comprises one of a noise elimination processor, a bright and dark difference reduction processor, an image enhancement processor, an enlargement processor and a smoothing processor, all of which are for processing the multivalued image data before being supplied to said binarization means.

Claim 59

The image processing method as claimed in any one of claims 13 , 14 and 15 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 60

The image processing method as claimed in claim 16 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 61

The image processing method as claimed in any one of claims 19 , 20 and 21 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 62

The image processing method as claimed in claim 22 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 63

The recording medium having computer readable image processing program code means as claimed in any one of claims 25 , 26 and 27 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 64

The recording medium having computer readable image processing program code means as claimed in claim 28 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 65

The recording medium having computer readable image processing program code means as claimed in any one of claims 31 , 32 and 33 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.

Claim 66

The recording medium having computer readable image processing program code means as claimed in claim 34 , wherein said multivalued image processing step further comprises one of a noise elimination step, a bright and dark difference reduction step, an image enhancement step, an enlargement step and a smoothing step, all of which are for processing the multivalued image data before the binarization.