Image processing apparatus with conversion and reconversion of the number of bits per pixel

Claim 2

An image processing apparatus comprising: converter means for receiving data digitized with m levels (m≧2) and converting said data into data of n levels (n>m); data processing means for executing data processing on the data of n levels produced by said converter means; and digitizing means for digitizing the data of n levels, data-processed by said data processing means, again into redigitized data of m levels, wherein said digitizing means is adapted to determine an average of a predetermined area, utilizing data already redigitized to m levels, and to convert the data of n levels, produced by said data processing means, into the redigitized data of m levels based on said average.

Claim 3

An apparatus according to claim 1, wherein said converter means is adapted to receive binary data subjected to binary digitization, and to convert said binary data into multi-level data, utilizing a weighting mask having a weighted distribution.

Claim 4

An apparatus according to claim 2, wherein said digitizing means is adapted to binary-digitize the multi-level data produced by said data processing means.

Claim 5

An apparatus according to claim 3, wherein said digitizing means is adapted to determine the average density in a predetermined area, based on plural binary data already subjected to binary digitization, and to binary-digitize the multi-level data produced by said data processing means, utilizing said average density as a threshold value.

Claim 6

An apparatus according to claim 3, wherein said data processing means is adapted to apply a predetermined editing process to the multi-level data obtained by said converter means, and said digitizing means is adapted to binary-digitize the multi-level data which has been subjected to said editing process by said data processing means.

Claim 7

An apparatus according to claim 1, further comprising correction means for compensating for error generated in the digitization of the data of n levels into the data of m levels by said digitizing means.

Claim 8

An apparatus according to claim 6, wherein said correction means is adapted to compensate for said error only when said error is larger than a predetermined value.

Claim 9

An image processing apparatus comprising: first calculation means for determining a weighted average for each pixel by multiplication and addition of plural binary image data in the vicinity of an object pixel and weighting coefficients of a predetermined distribution; input means for applying a predetermined image processing to the average calculated by said first calculation means, considering said average as a multi-level image value, and entering a multi-level value datum of said object pixel; second calculation means for determining the average density of a predetermined area; binary digitizing means for again binary-digitizing the multi-level value datum of said object pixel, based on the average density obtained by said second calculation means; and correction means for compensating for the error generated in the binary digitization of the datum of said object pixel by said binary digitizing means, wherein said second calculation means determines the average density using binary data rebinarized by said binary digitizing means.

Claim 10

An image processing apparatus comprising: first calculation means for determining a weighted average for each pixel by multiplication and addition of plural binary image data in the vicinity of an object pixel and weighting coefficients of a predetermined distribution; input means for applying a predetermined image processing to the average calculated by said first calculation means, considering said average as a multi-level image value, and entering a multi-level value datum of said object pixel; second calculation means for determining the average density of a predetermined area; binary digitizing means for again binary-digitizing the multi-level value datum of said object pixel, based on the average density obtained by said second calculation means; and correction means for compensating for the error generated in the binary digitization of the datum of said object pixel by said binary digitizing means, wherein said second calculation means determines the average density using binary data rebinarized by said binary digitizing means.

Claim 11

An image processing apparatus comprising: converter means for receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing means for executing data processing on the data of n levels produced by said converter means; and digitizing means for digitizing the data of n levels, data-processed by said data processing means, again into redigitized data of m levels, wherein said digitizing means digitizes the data of n levels produced by said data processing means into the redigitized data of m levels utilizing data already redigitized to m levels and an error generated in the digitization, and wherein said digitizing means is adapted to determine an average density in a predetermined area, based on plural redigitized data from said digitizing means, and to digitize the data of n levels produced by said data processing means, utilizing the average density.

Claim 12

An image processing apparatus comprising: converter means for receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing means for executing data processing on the data of n levels produced by said converter means; and digitizing means for digitizing the data of n levels, data-processed by said data processing means, again into redigitized data of m levels, wherein said digitizing means digitizes the data of n levels produced by said data processing means into the redigitized data of m levels utilizing data already redigitized to m levels and an error generated in the digitization, and wherein said digitizing means is adapted to determine an average density in a predetermined area, based on plural redigitized data from said digitizing means, and to digitize the data of n levels produced by said data processing means, utilizing the average density.

Claim 13

An apparatus according to claim 9, wherein m=2 and wherein said converter means is adapted to receive binary data which has been subjected to binary digitization, and to convert the binary data into the data of n levels utilizing a weighting mask having a weighted distribution.

Claim 14

An apparatus according to claim 10, wherein said digitizing means is adapted to binary-digitize the data of n levels produced by said data processing means.

Claim 15

An apparatus according to claim 11, wherein said data processing means is adapted to apply a predetermined editing process to the data of n levels obtained by said converter means, and wherein said digitizing means is adapted to binary-digitize the data of n levels which has been subjected to said editing process by said data processing means.

Claim 16

An image processing method comprising the steps of: receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing the data of n levels produced in said receiving and converting step; and digitizing the data of n levels, data-processed in said data processing step, again into redigitized data of m levels, wherein, in said digitizing step, an average of a predetermined area is determined, utilizing data already redigitized to m levels, and the data of n levels produced in said data processing step is converted into the redigitized data of m levels based on the average.

Claim 17

An image processing method comprising the steps of: receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing the data of n levels produced in said receiving and converting step; and digitizing the data of n levels, data-processed in said data processing step, again into redigitized data of m levels, wherein, in said digitizing step, an average of a predetermined area is determined, utilizing data already redigitized to m levels, and the data of n levels produced in said data processing step is converted into the redigitized data of m levels based on the average.

Claim 18

An image processing method comprising the steps of: receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing the data of n levels produced in said receiving and converting step; and digitizing the data of n levels, data-processed in said data processing step, again into redigitized data of m levels, wherein, in said digitizing step, the data of n levels produced in said data processing step is digitized into the redigitized data of m levels utilizing data already redigitized to m levels and an error generated in the digitization, and wherein said digitizing step is adapted to determine an average density in a predetermined area, based on plural redigitized data from said digitizing step, and to digitize the data of n levels produced by said data processing step, utilizing the average density.

Claim 19

An image processing method comprising the steps of: receiving data digitized with m levels (m≧2) and converting the data into data of n levels (n>m); data processing the data of n levels produced in said receiving and converting step; and digitizing the data of n levels, data-processed in said data processing step, again into redigitized data of m levels, wherein, in said digitizing step, the data of n levels produced in said data processing step is digitized into the redigitized data of m levels utilizing data already redigitized to m levels and an error generated in the digitization, and wherein said digitizing step is adapted to determine an average density in a predetermined area, based on plural redigitized data from said digitizing step, and to digitize the data of n levels produced by said data processing step, utilizing the average density.