Real time video image processing system

In a video system with a video image defined by an array comprising lines of pixel values associated with picture elements or pixels, with array position coordinates (X.sub.m, Y.sub.n) (m=0,1,2, . . . , M';

• n=0,1,2, . . . , N'), where each video image is formed by the combination of two fields with each field containing a subset of lines of pixels and the two lines of pixels comprising the array of pixels, where each line of pixels of one field is positioned between and adjacent to two lines of pixels of a second field, where a first field of pixel values is displayed on a video screen during time intervals t.sub.0, t.sub.2, t.sub.4 and a second field of pixel values is displayed at time intervals t.sub.1, t.sub.3, t.sub.5 and where t.sub.5 precedes t.sub.4 which precedes t.sub.3 which precedes t.sub.2 which precedes t.sub.1 which precedes t.sub.0 and where a pixel value of a pixel on line number k at horizontal position j with array position (x.sub.j, y.sub.k) has an associated pixel value pv(x.sub.j,y.sub.k ;t) that is displayed during time interval t, a method of constructing a synthetic pixel value of a non-existent pixel at position (x.sub.j,y.sub.k) in a line of the second field that takes account of relative motion or change in time manifested by pixel values adjacent to array position (x.sub.j,y.sub.k), the method comprising the steps of:
• determining the rapidity of change with time of each of the pixel values at each pixel position (x.sub.j,y.sub.k-1) and (x.sub.j, y.sub.k+1) between the time interval t.sub.0 [(t.sub.0, t.sub.1)={t/t.sub.0 <t<t.sub.1 }] and the time interval t.sub.2 and at each pixel position (x.sub.j-1, y.sub.K) between time intervals t.sub.1 and t.sub.3 ;
• obtaining the pixel value pv(x.sub.j+1, y.sub.k ;
• t) for t in the interval (t.sub.t ', t.sub.2 ')={t.sub.1 <t<t.sub.2 '};
• introducing a parameter .beta.(0.ltorsim..beta..ltorsim.1) that is either continuous or has at least three distinct values .beta.=0, .beta.=1, and .beta..sub.i (0<.beta.i<1);
• setting .beta.=0 if substantially no change with time is perceived in any of the pixel values at positions (x.sub.j, y.sub.y-1), (x.sub.j, y.sub.k+1), (x.sub.j-1, y.sub.k, and (x.sub.j, y.sub.k), setting .beta.=1 if rapid change with time is perceived at any of those pixel positions, and setting .beta. equal to an intermediate value .beta..sub.i if the change with time perceived at least one of these pixel positions is non-zero but the change with time perceived at each of these pixel positions is less than rapid;
• forming the sum ##EQU42## as the synthetic pixel value;
• and displaying the synthetic value for a pixel position in place of at least one pixel of the video image.

In a video system with a video image defined by a two-dimensional array, with array positions (x.sub.m, y.sub.n), of picture elements or pixels and with each pixel having an associated pixel value pv that contributes to formation of the video image, a method of forming a desired signal value S of pixel values for up to a predetermined number M of pixels adjacent to a given target pixel, with weight coefficients that change from one target pixel to another target pixel and may change from one time interval .DELTA.t.sub.1 to another time interval .DELTA.t.sub.2, where the lengths of the time intervals .DELTA.t.sub.1 and .DELTA.t.sub.2 are each of the order of 74 nanoseconds, the method consisting of:

• providing a filter including a predetermined number K of arrays (k=1,2, . . . , K) of weight coefficients C(J,k).sub.j-1.sup.j.sbsp. stored in a random access memory system, with the weight coefficients being jk real numbers that satisfy the normalization constraint ##EQU43## providing coefficient choice means whereby an array C(j,k).sub.j-1.sup.j.sbsp.k of weight coefficients may be chosen to form the weighted sum of j.sub.k pixel values pv(x.sub.m,y.sub.n) of pixels with positions (x.sub.m,y.sub.n) adjacent to or in a predetermined neighborhood N(x.sub.T,y.sub.T) Of the position (x.sub.T,y.sub.T) of the target pixel;
• providing coefficient change means whereby an array of weight coefficients can be changed in a time interval .DELTA.t that is substantially no greater than 74 nanoseconds
• forming the desired signal value sum ##EQU44## and displaying the desired signal value in place of at least one of the predetermined number M of pixels in the video image.

A method of interpolating pixel signals in a video system for displaying a video image means of an array of picture elements each having an associate pixel signal, comprising the steps of:

• choosing a portion of pixels from the array;
• providing a plurality of sets of low pass filters, there being one filter in each set for each pixel of the portion;
• providing a multiplexer for matching each of the filters to an associated pixel signal in the portion;
• and
• forming an interpolated pixel signal as a function of the stored pixel signals of the portion by passing the portion of pixel signals through the matched filters.

In a video signal having a video image defined by an array of picture elements each having a pixel value, a method of displaying a pixel that takes into account motion manifested by pixel positions comprising the steps of:

• determining the rapidity of change with time of the pixel positions at each of a plurality of picture elements over a particular time interval;
• introducing three output signals associated respectively with no change, rapid change, and intermediate change in the particular time interval of pixel positions, the third signal being a function of the rapidity of change in the step of determining;
• forming a synthetic value for each pixel position, the synthetic value being a function of the particular time interval, the output signal, and the pixel positioning in the particular time interval;
• and
• displaying the synthetic value for each pixel position in place of the original pixel.

In a system for filtering a digital video signal including pixels dv(x.sub.j), a method of forming a desired signal S of values for up to a predetermined number M of pixels adjacent to a given pixel, with weight coefficients that change from one pixel to another pixel and may change from a first time interval to a second time interval, where the length of both time intervals is equal to a cycle time of the video system, the method comprising the steps of:

• providing a predetermined number K of digital filter arrays (k=1,2, . . . , K) of weight coefficients {C(j,k)}j-1 stored in a memory system;
• providing a coefficient choice whereby an array {C(j,k)}.sub.j-1.sup.m of weight coefficients are chosen to form the
• weighted sum of M pixel values dv(x.sub.m) of pixels with positions (x.sub.m) adjacent to or in a predetermined neighborhood of the position (x.sub.T) of a particular pixel;
• changing coefficients whereby an array of weight coefficients can be changed in a time interval that is substantially no greater than the first time interval;
• forming the desired signal value sum ##EQU45## for the number K;
• displaying the desired signal value in place of at least one of the M pixel values in the video signals;
• and
• wherein the step of changing coefficients is performed by one integrated circuit chip.

A method of filtering a digital video signal defined by a plurality of pixels each having an associated pixel value, comprising the steps of:

• providing a predetermined number of arrays of digital filters in a plurality of storage locations;
• selecting one of the arrays at repeated time intervals of no greater than 74 nanoseconds;
• for each pixel in the digital video signal, applying the selected array to the pixel;
• and
• displaying the filtered video signals in place of a portion of the digital video signal.