Image interpolation apparatus

Claim 3

The method as described in claim 1, wherein the original document image source is a scanner deriving said video image signals as a function of sensed reflected light from an illuminated document.

Claim 4

The method as described in claim 1, wherein the page memory is a DRAM.

Claim 5

The method as described in claim 1, wherein the interpolation requirement is a rotation of the original image.

Claim 6

The method as described in claim 1, wherein the interpolation requirement is a scaling of the original image.

Claim 7

The method as described in claim 1, wherein the interpolation calculator generates the new video image signal intensity in accordance with the function: P.sub.new =P.sub.n,m (1-a-b+ab)+P.sub.n+1,m (a-ab) +P.sub.n,m +(b-ab)+P.sub.n+1,m+1 (ab) where P refers to the video image signal intensity at a subscripted location.

Claim 8

Apparatus for providing interpolated video image signals from original video image signals representing an original document image, each video image signal defined in terms of intensity and position in the original document image, comprising: means for receiving an original document image from an original video image signal source; page memory means, operatively connected to said receiving means for storing a sufficient number of scan lines of video image signals representing a page of original image received therefrom, said number large enough to overlap an entire scan line of interpolated video signals; means receiving from an external source a set of six values indicating: a slow scan initial value Xinit, a fast scan initial value Yinit, a fast scan x offset value FSx, a fast scan y offset value FSy, a slow scan x offset value SSx, and a slow scan y offset value SSy;, a bilinear sequencer calculating for each new video image signal, from said received values a reference video image signal within the document image, and a pair of interpolation coefficients for interpolating new video image signals, and providing an output indicative thereof to said page memory; wherein the bilinear sequencer calculates from said received values a reference video image signals within the image, and a pair of interpolation coefficients for interpolating new video image signals values in accordance with the functions: a=Fraction of [Xinit+SSx (scanline)+FSx(pixel)] b=Fraction of [Yinit+SSy(scanline)+FSy(pixel)] n=Integer [Xinit+SSx(scanline)+FSx(pixel)] m=Integer of [Yinit+SSy(scanline)+FSy(pixel)] where a is a fast scan coefficient of a video image signal value b is a slow scan coefficient of the video image signal value n is the position of the reference video image signal in the fast scan direction; and m is the position of the reference video image signal in the slow scan direction; pixel is the position of the new video image signal in a scan line of the new image; and scanline is the position of the new scan line in the image; means, responsive to the output of said bilinear sequencer, for retrieving to an interpolation calculator from the page memory a set of original video image signals including said reference video image signal, and three other video image signals whose position is a predetermined function of the position of said reference video image signal for each new video image signal; and an interpolation calculator generating a new video image signal as a function of the set of original video image signals directed thereto by the bilinear sequencer.

Claim 9

Apparatus for providing interpolated video image signals from original video image signals representing an original document image, each video image signal defined in terms of intensity and position in the original document image, comprising: means for receiving an original document image from an original video image signal source; page memory means, operatively connected to said receiving means for storing a sufficient number of scan lines of video image signals representing a page of original image received therefrom, said number large enough to overlap an entire scan line of interpolated video signals; means receiving from an external source a set of six values indicating: a slow scan initial value Xinit, a fast scan initial value Yinit, a fast scan x offset value FSx, a fast scan y offset value FSy, a slow scan x offset value SSx, and a slow scan y offset value SSy;, a bilinear sequencer calculating for each new video image signal, from said received values a reference video image signal within the document image, and a pair of interpolation coefficients for interpolating new video image signals, and providing an output indicative thereof to said page memory; wherein the bilinear sequencer calculates from said received values a reference video image signals within the image, and a pair of interpolation coefficients for interpolating new video image signals values in accordance with the functions: a=Fraction of [Xinit+SSx (scanline)+FSx(pixel)] b=Fraction of [Yinit+SSy(scanline)+FSy(pixel)] n=Integer [Xinit+SSx(scanline)+FSx(pixel)] m=Integer of [Yinit+SSy(scanline)+FSy(pixel)] where a is a fast scan coefficient of a video image signal value b is a slow scan coefficient of the video image signal value n is the position of the reference video image signal in the fast scan direction; and m is the position of the reference video image signal in the slow scan direction; pixel is the position of the new video image signal in a scan line of the new image; and scanline is the position of the new scan line in the image; means, responsive to the output of said bilinear sequencer, for retrieving to an interpolation calculator from the page memory a set of original video image signals including said reference video image signal, and three other video image signals whose position is a predetermined function of the position of said reference video image signal for each new video image signal; and an interpolation calculator generating a new video image signal as a function of the set of original video image signals directed thereto by the bilinear sequencer.

Claim 10

The apparatus as described in claim 7, wherein the original document image source is a scanner deriving said video image signals as a function of sensed reflected light from an illuminated document.

Claim 11

The apparatus as described in claim 7, wherein the page memory is a DRAM.

Claim 12

The apparatus as described in claim 7, wherein the interpolation requirement is a rotation of the original image.

Claim 13

The apparatus as described in claim 7, wherein the interpolation requirement is a scaling of the original document image.

Claim 14

The apparatus as described in claim 7, wherein the interpolation calculator calculates the new video image signal value in accordance with the function: P.sub.new =P.sub.n,m (1-a-b+ab)+P.sub.n+1,m (a-ab)+P.sub.n,m +(b-ab)+P.sub.n+1,m+1 (ab) where P refers to the video image signal value at a subscripted location.