Hybrid interpolation and non-interpolation method and apparatus for image enlarging and contracting

An apparatus for processing image data to enlarge and contract an original image, represented by the data, by P times in an X-axis direction and Q times in a Y-axis direction while interpolating the data, P and Q denoting arbitrary positive rational numbers respectively, the apparatus comprising:

• means for allowing a supposition that each of regions among pixels of the original image is divided into sub areas having a number N by M, that is, N in the X-axis direction and M in a Y-axis direction, N denoting an arbitrary integer equal to or greater than 2, M denoting an arbitrary integer equal to or greater than 1;
• an N-time interpolation enlarging means for executing an interpolation process determined by an original-image sub area corresponding to a pixel of an enlargement/contraction-resultant image while simultaneously generating a plurality of pieces of process-resultant data representing a part of an image enlarged from the original image by N times in the X-axis direction;
• an arbitrary-magnification enlarging/contracting means for subjecting the plurality of the pieces of the process-resultant data to image enlargement and contraction at an arbitrary magnification in the X-axis direction without executing interpolation, and thereby for processing the plurality of the pieces of the process-resultant data to enlarge and contract an image, represented by the plurality of the pieces of the process-resultant data, by P/N times in the X-axis direction;
• a sub-area row calculating means for calculating a row number of an original-image sub area corresponding to pixels in a same row of an enlargement/contraction-resultant image, the row extending in the X-axis direction;
• a reference data address generating means for generating addresses of pixel data on a source-image memory to which the N-time interpolation enlarging means refers;
• a selecting means for selecting a plurality of data from among data read out from the source-image memory as reference data, wherein the reference data selected by the selecting means are referred to by the N-time interpolation enlarging means every process;
• a write data address generating means for generating an address on an object-image memory into which data processed by the arbitrary-magnification enlarging/contracting means is written;
• and
• a control means for controlling transfer of the plurality of the image data from the N-time interpolation enlarging means to the arbitrary-magnification enlarging/contracting means.

An apparatus for processing image data to enlarge and contract an original image, represented by the data, by P times in an X-axis direction and Q times in a Y-axis direction while interpolating the data, P and Q denoting arbitrary positive rational numbers respectively, the apparatus comprising:

• means for allowing a supposition that each of regions among pixels of the original image is divided into sub areas having a number N by M, that is, N in the X-axis direction and M in a Y-axis direction, N denoting an arbitrary integer equal to or greater than 2, M denoting an arbitrary integer equal to or greater than 1;
• an N-time interpolation enlarging means for executing an interpolation process determined by an original-image sub area corresponding to a pixel of an enlargement/contraction-resultant image while simultaneously generating a plurality of pieces of process-resultant data representing a part of an image enlarged from the original image by N times in the X-axis direction;
• an arbitrary-magnification enlarging/contracting means for subjecting the plurality of the pieces of the process-resultant data to image enlargement and contraction at an arbitrary magnification in the X-axis direction without executing interpolation, and thereby for processing the plurality of the pieces of the process-resultant data to enlarge and contract an image, represented by the plurality of the pieces of the process-resultant data, by P/N times in the X-axis direction;
• a sub-area row calculating means for calculating a row number of an original-image sub area corresponding to pixels in a same row of an enlargement/contraction-resultant image, the row extending in the X-axis direction;
• a reference data address generating means for generating addresses of pixel data on a source-image memory to which the N-time interpolation enlarging means refers;
• a selecting means for selecting a plurality of data from among data read out from the source-image memory as reference data, wherein the reference data selected by the selecting means are referred to by the N-time interpolation enlarging means every process;
• a write data address generating means for generating an address on an object-image memory into which data processed by the arbitrary-magnification enlarging/contracting means is written;
• a control means for controlling transfer of the plurality of the image data from the N-time interpolation enlarging means to the arbitrary-magnification enlarging/contracting means;
• and
• an interpolation information adding means for adding information to original-image data read out from the source-image memory, the information representing the sub-area row number calculated by the sub-area row calculating means;
• wherein the N-time interpolation enlarging means processes the original-image data into the plurality of the pieces of the process-resultant data on the basis of the information added by the interpolation information adding means, and the arbitrary-magnification enlarging/contracting means processes the plurality of the pieces of the process-resultant data to enlarge and contract an image, represented by the plurality of the pieces of the process-resultant data, by P/N times in the X-axis direction.

An apparatus for processing image signals representative of image data to enlarge and contract an original image, represented by the image data, by P times in an X-axis direction while interpolating the image data, P denoting a predetermined positive rational number, the image data representing states of respective pixels of the original image, the apparatus comprising:

• means for dividing each of regions among pixels of the original image into sub areas having a number of N by M, that is, N in the X-axis direction and M in a Y-axis direction perpendicular to the X-axis direction, N denoting a predetermined integer equal to or greater than 2, M denoting a predetermined integer equal to or greater than 1;
• an N-time interpolation enlarging means receiving said image signals for interpolating the image data of said image signals into first process-resultant data representing states of respective pixels of a first process-resultant image enlarged from the original image by N times in the X-axis direction, wherein the N-time interpolation enlarging means comprises means for determining a sub area of the original image which corresponds to each interpolated pixel of the first process-resultant image, means for determining a state of the interpolated pixel of the first-process-resultant image on the basis of states of pixels of the original image which are adjacent to the determined sub area of the original image, and means for simultaneously generating a plurality of signals representing a plurality of pieces of the first process-resultant data which represent states of a plurality of pixels of the first process-resultant image;
• and
• a P/N-time enlarging/contracting means responsive to said plurality of signals from said interpolation enlarging means for processing said plurality of signals representing the first process-resultant data into further signals representing second process-resultant data without interpolation, the second process-resultant data representing states of respective pixels of a second process-resultant image enlarged or contracted from the first process-resultant image by P/N times in the X-axis direction, said enlarging/contracting means processing the pieces of the first process-resultant data to enlarge and contract an image represented thereby by P/N times in the X-axis direction.