Patent ID: 6091513
Filing Date: 2000-07-18
Classification: G06T

Abstract:
An image size converting apparatus comprising:a conversion magnification designating unit for designating a conversion magnification (K) to convert an original image having (P.times.Q) dots as a predetermined number of pixels in the vertical and horizontal directions into a target image of (M.times.N) dots as a different number of pixels in the vertical and horizontal directions;a resolution designating unit to designate a resolution of the target image;an image size designating unit to designate image sizes of the original image and the target image;a first magnification processing unit to magnify said original image to said target image through interpolation by simple repetition of pixels;a second magnification processing unit to magnify said original image to a virtual image of I(M.times.N) dots as the number of pixels in the vertical and horizontal directions by multiplying said (M.times.N)dots as the number of pixels in the vertical and horizontal directions of said target image by an integer (I) of 2 or larger when said original image is magnified to said target image and, thereafter, averaging the pixels on a unit basis of (I.times.I) dots as the number of pixels in the vertical and horizontal directions which coincides with said multiple (I) with respect to said virtual image, thereby calculating each pixel value of said target image;a first reduction processing unit to reduce said original image to said target image by simply thinning out pixels;a second reduction processing unit to magnify said original image to a virtual image of I(M.times.N) dots as the number of pixels in the vertical and horizontal directions by multiplying said (M.times.N) dots as the number of pixels in the vertical and horizontal directions of said target image by an integer (I) of 2 or larger when said original image is reduced to said target image and, thereafter, averaging the pixels on a unit basis of (I.times.I) dots as the number of pixels in the vertical and horizontal directions which coincides, with said multiple (I) with respect to said virtual image, thereby calculating each pixel value of said target image;a third reduction processing unit to magnify said original image to a virtual image of 2I(M.times.N) dots as the number of pixels in the vertical and horizontal directions by multiplying said (M.times.N) dots as the number of pixels in the vertical and horizontal directions of said target image by a value which is twice as large as said integer (I) of 2 or larger when said original image is reduced to said target image and, thereafter, averaging the pixels on a unit basis of 2(I.times.I) dots as the number of pixels in the vertical and horizontal directions which coincides with said multiple (I.times.2) with respect to said virtual image, thereby calculating each pixel value of said target image; anda process discriminating unit to select an optimum processing unit among said first magnification processing unit, said second magnification processing unit, said first reduction processing unit, said second reduction processing unit, and said third reduction processing unit on the basis of said conversion magnification, said resolution, and said image size, thereby allowing the selected processing unit to execute a converting process.