Method for enlarging an image stored in run representation form

Claim 1

A method for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, comprising the steps of: storing the rows of said image as a plurality of run ends with each row being represented as a sequence of values corresponding to the unnormalized white and black run ends; partially enlarging said binary image along said first axis by altering the value of each unnormalized run end in the respective rows by a predetermined factor F1; further enlarging said binary image along said second axis by creating additional rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the corresponding run ends of the rows of the partially enlarged image adjacent the additional interpolated rows to determine the positions of the white and black run ends on the interpolated rows, the number and distribution of said interpolated rows being chosen so as to produce enlargement along said second axis by a predetermined factor F2; and storing said enlarged size image generated by the above steps in said unnormalized run end form.

Claim 2

A method for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, comprising the steps of: storing the rows of said image as a plurality of run ends with each row being represented as a sequence of values corresponding to the unnormalized white and black run ends; partially enlarging said binary image along said first axis by altering the value of each unnormalized run end in the respective rows by a predetermined factor F1; further enlarging said binary image along said second axis by creating additional rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the corresponding run ends of the rows of the partially enlarged image adjacent the additional interpolated rows to determine the positions of the white and black run ends on the interpolated rows, the number and distribution of said interpolated rows being chosen so as to produce enlargement along said second axis by a predetermined factor F2; and storing said enlarged size image generated by the above steps in said unnormalized run end form.

Claim 9

A method for enlarging a binary digital image along one axis thereof by a predetermined factor F, said binary image having lines of picture elements or pels, said lines arranged adjacently along said one axis and containing runs of white and black pels, comprising the steps of: initializing a buffer with unnormalized run end values corresponding to those of the runs of white and black pels in a number of adjacent lines selected from said image, said lines comprising two extreme lines disposed respectively at the two ends of sid buffer along said one axis; discarding one of the extreme lines from one end of said buffer; reading the unnormalized run end values describing a line of said image adjacent said other extreme line, and adding said run end values of said adjacent line to the other end of said buffer following the other extreme line; interpolating zero or more lines between two selected lines of said buffer, in accordance with said predetermined enlargement factor F along said one axis, by creating respective run end values to describe each interpolated line; selecting the run end locations for said interpolated lines being generated by examining the image lines in said buffer, in order to detect edge pel position changes along said axis and smoothing edges by accordingly adding or removing pels from said edges; storing said zero or more interpolated lines and said selected line nearer said other end of said buffer in run end form; and repeating said discarding, reading, adding, interpolating, selecting, and storing steps for all lines of said image.

Claim 10

A method for enlarging a binary digital image along one axis thereof by a predetermined factor F, said binary image having lines of picture elements or pels, said lines arranged adjacently along said one axis and containing runs of white and black pels, comprising the steps of: initializing a buffer with unnormalized run end values corresponding to those of the runs of white and black pels in a number of adjacent lines selected from said image, said lines comprising two extreme lines disposed respectively at the two ends of sid buffer along said one axis; discarding one of the extreme lines from one end of said buffer; reading the unnormalized run end values describing a line of said image adjacent said other extreme line, and adding said run end values of said adjacent line to the other end of said buffer following the other extreme line; interpolating zero or more lines between two selected lines of said buffer, in accordance with said predetermined enlargement factor F along said one axis, by creating respective run end values to describe each interpolated line; selecting the run end locations for said interpolated lines being generated by examining the image lines in said buffer, in order to detect edge pel position changes along said axis and smoothing edges by accordingly adding or removing pels from said edges; storing said zero or more interpolated lines and said selected line nearer said other end of said buffer in run end form; and repeating said discarding, reading, adding, interpolating, selecting, and storing steps for all lines of said image.

Claim 11

A method for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said original binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, and then reducing the enlarged binary image to the original binary image size, such that the image that results upon reductiin after said original binary image has been enlarged is identical to said original binary image, comprising the steps of: storing the rows of said original binary image as run end representations, in which each row is represented as a sequence of integer values corresponding to the unnormalized white and black run ends; enlarging said original binary image by the steps of: enlarging each row of said original binary image along said first axis by altering the integer value of each run end in the run end representation corresponding to each respective row by a predetermined factor F1, in such manner that for each pel represented in said each respective row there exists a pel at a known position in the produced enlarged image row having the same binary value as said pel represented in said each respective row; further enlarging said original binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends in the interpolated rows, so as to produce enlargement of said original binary image along said second axis by a predetermined factor F2; storing the enlarged image generated by the above steps in run end form; and reducing said enlarged image to a reduced image identical to said original binary image and of said original size by the steps of: dividing said enlarged image into a plurality of strips parallel to said first axis, each strip containing one row which was obtained by enlargement of an original image row and zero or more interpolated rows; dividing each of said strips into blocks, each block corresponding to an original image pel and containing a pel of known position corresponding in binary value to said original image pel; and creating said reduced image by providing a pel for each said block and assigning a binary value to said pel equal to the value of the pel of known position in the block corresponding to said pel.

Claim 12

A method for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said original binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, and then reducing the enlarged binary image to the original binary image size, such that the image that results upon reductiin after said original binary image has been enlarged is identical to said original binary image, comprising the steps of: storing the rows of said original binary image as run end representations, in which each row is represented as a sequence of integer values corresponding to the unnormalized white and black run ends; enlarging said original binary image by the steps of: enlarging each row of said original binary image along said first axis by altering the integer value of each run end in the run end representation corresponding to each respective row by a predetermined factor F1, in such manner that for each pel represented in said each respective row there exists a pel at a known position in the produced enlarged image row having the same binary value as said pel represented in said each respective row; further enlarging said original binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends in the interpolated rows, so as to produce enlargement of said original binary image along said second axis by a predetermined factor F2; storing the enlarged image generated by the above steps in run end form; and reducing said enlarged image to a reduced image identical to said original binary image and of said original size by the steps of: dividing said enlarged image into a plurality of strips parallel to said first axis, each strip containing one row which was obtained by enlargement of an original image row and zero or more interpolated rows; dividing each of said strips into blocks, each block corresponding to an original image pel and containing a pel of known position corresponding in binary value to said original image pel; and creating said reduced image by providing a pel for each said block and assigning a binary value to said pel equal to the value of the pel of known position in the block corresponding to said pel.

Claim 15

A system for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, comprising: means for storing the rows of said binary image as a plurality of run end representations, in which each row is represented as a sequence of values corresponding to the unnormalized white and black run ends; first means for partially enlarging said binary image by altering the value of each run end in the run end representations of the respective rows to achieve enlargement along said first axis by a predetermined factor F1; second means for further enlarging said binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by said first means, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends on the interpolated rows, so as to produce enlargement along said second axis by a predetermined factor F2; and means for storing said enlarged size image, generated by said foregoing means, in unnormalized run end form.

Claim 16

A system for enlarging a binary digital image along first and second axes thereof by factors of F1 and F2, respectively, said binary image having rows of picture elements or pels, said rows arranged adjacently along said second axis and containing runs of white and black pels, comprising: means for storing the rows of said binary image as a plurality of run end representations, in which each row is represented as a sequence of values corresponding to the unnormalized white and black run ends; first means for partially enlarging said binary image by altering the value of each run end in the run end representations of the respective rows to achieve enlargement along said first axis by a predetermined factor F1; second means for further enlarging said binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by said first means, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends on the interpolated rows, so as to produce enlargement along said second axis by a predetermined factor F2; and means for storing said enlarged size image, generated by said foregoing means, in unnormalized run end form.

Claim 22

A system for enlarging a binary digital image, in the form of a plurality of rows of picture elements or pels containing runs of white and black pels, along first and second axes thereof by factors of F1 and F2, respectively, and then reducing said binary image to its original size, such that the image that results upon reduction after said binary image has been enlarged is identical to said original binary image, comprising: means for storing the rows of said original binary image as run end representations, in which each row is represented as a sequence of integer values corresponding to the unnormalized white and black run ends; means for enlarging said original binary image comprising: first means for enlarging each row of said original binary image along said first axis by altering the integer value of each run end in the run end representation corresponding to each respective row by a predetermined factor F1, in such manner that for each pel represented in said each respective row there exists a pel at a known position in the produced enlarged image row having the same binary value as said pel represented in said each respective row; second means for further enlarging said original binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends in the interpolated rows, so as to produce enlargement of said original binary image along said second axis by a predetermined factor F2; means for storing the enlarged image generated by said first and second enlarging means in run end form; and means for reducing said enlarged image to a reduced image identical to said original binary image and of said original size comprising: first means for dividing said enlarged image into a plurality of strips parallel to said first axis, each strip containing one row which was obtained by enlargement of an original image row and zero or more interpolated rows; second means for dividing each of said strips into blocks, each block corresponding to an original image pel and containing a pel of known position corresponding in binary value to said original image pel; and means for creating said reduced image by providing a pel for each said block and assigning a binary value to said pel equal to the value of the pel of known position in the block corresponding to said pel.

Claim 23

A system for enlarging a binary digital image, in the form of a plurality of rows of picture elements or pels containing runs of white and black pels, along first and second axes thereof by factors of F1 and F2, respectively, and then reducing said binary image to its original size, such that the image that results upon reduction after said binary image has been enlarged is identical to said original binary image, comprising: means for storing the rows of said original binary image as run end representations, in which each row is represented as a sequence of integer values corresponding to the unnormalized white and black run ends; means for enlarging said original binary image comprising: first means for enlarging each row of said original binary image along said first axis by altering the integer value of each run end in the run end representation corresponding to each respective row by a predetermined factor F1, in such manner that for each pel represented in said each respective row there exists a pel at a known position in the produced enlarged image row having the same binary value as said pel represented in said each respective row; second means for further enlarging said original binary image along said second axis by creating run end representations representing rows interpolated between the rows of the partially enlarged image produced by the preceding step, using the run ends of the rows of the partially enlarged image adjacent each interpolated row to determine the positions of the white and black run ends in the interpolated rows, so as to produce enlargement of said original binary image along said second axis by a predetermined factor F2; means for storing the enlarged image generated by said first and second enlarging means in run end form; and means for reducing said enlarged image to a reduced image identical to said original binary image and of said original size comprising: first means for dividing said enlarged image into a plurality of strips parallel to said first axis, each strip containing one row which was obtained by enlargement of an original image row and zero or more interpolated rows; second means for dividing each of said strips into blocks, each block corresponding to an original image pel and containing a pel of known position corresponding in binary value to said original image pel; and means for creating said reduced image by providing a pel for each said block and assigning a binary value to said pel equal to the value of the pel of known position in the block corresponding to said pel.

Claim 26

A system for enlarging a binary digital image along one axis thereof by a predetermined factor F, said binary image having lines of picture elements or pels, said lines arranged adjacently along said one axis and containing runs of white and black pels, comprising: means for initializing a buffer with unnormalized run end values corresponding to those of the runs of white and black pels in a number of adjacent lines selected from said image, said lines comprising two extreme lines disposed respectively at the two ends of said buffer along said one axis; means for discarding one of the extreme lines from one end of said buffer; means for reading the unnormalized run end values describing a line of said image adjacent said other extreme line, and adding said run end values of said adjacent line to the other end of said buffer following the other extreme line; means for interpolating zero or more lines between two selected lines of said buffer, in accordance with said predetermined enlargement factor F along said one axis, by creating respective run end values to describe each interpolated line; means for selecting the run end locations for said interpolated lines being generated by examining the image lines in said buffer, in order to detect edge pel position changes along said axis and smoothing edges by accordingly adding or removing pels from said edges; means for storing said zero or more interpolated lines and said selected line nearer said other end of said buffer in run end form; and means for repeatedlyactuating said discarding, reading, adding, interpolating, selecting, and storing means for all lines of said image.

Claim 27

A system for enlarging a binary digital image along one axis thereof by a predetermined factor F, said binary image having lines of picture elements or pels, said lines arranged adjacently along said one axis and containing runs of white and black pels, comprising: means for initializing a buffer with unnormalized run end values corresponding to those of the runs of white and black pels in a number of adjacent lines selected from said image, said lines comprising two extreme lines disposed respectively at the two ends of said buffer along said one axis; means for discarding one of the extreme lines from one end of said buffer; means for reading the unnormalized run end values describing a line of said image adjacent said other extreme line, and adding said run end values of said adjacent line to the other end of said buffer following the other extreme line; means for interpolating zero or more lines between two selected lines of said buffer, in accordance with said predetermined enlargement factor F along said one axis, by creating respective run end values to describe each interpolated line; means for selecting the run end locations for said interpolated lines being generated by examining the image lines in said buffer, in order to detect edge pel position changes along said axis and smoothing edges by accordingly adding or removing pels from said edges; means for storing said zero or more interpolated lines and said selected line nearer said other end of said buffer in run end form; and means for repeatedlyactuating said discarding, reading, adding, interpolating, selecting, and storing means for all lines of said image.