Converter and method for converting video signals of interlace format to video signals of progressive format

Claim 2

A converter for converting video signals of an interlace format to video signals of a progressive format, comprising: an intra-field converting means for intra-field converting a video signal of said interlace format into a video signal of said progressive format; and an adaptive temporal filtering means for temporally filtering said video signal of said progressive format such that as a degree of image movement in images represented by said video signal of said progressive format increases, a lesser degree of temporal filtering is performed, and said adaptive temporal filtering means determining a progressive pixel value as a function of a first product of a first temporal coefficient and a pixel value of a current frame of said video signal of said progressive format and a second product of a second temporal coefficient and at least one pixel of at least one previous frame of said video signal of said progressive format.

Claim 3

The converter of claim 1, wherein said adaptive temporal filtering means performs filtering between successive frames in said progressive format.

Claim 4

The converter of claim 1, wherein said intra-field converter changes a horizontal sample rate of each field of said video signal of said interlace format and changes a number of lines of each field of said video signal of said interlace format.

Claim 5

The converter of claim 1, further comprising: edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and spatial expander means for determining a spatially expanded difference value based on output of said edge detecting means and said video signal of said progressive format; and wherein said adaptive temporal filtering means filters said video signal of said progressive format based on output of said spatial expander means.

Claim 6

The converter of claim 4, further comprising: delay means for delaying said video signal of said progressive format for a predetermined period of time; and a subtractor for subtracting output of said delay means from said video signal of said progressive format to obtain a difference signal; and wherein said spatial expander means determines said spatially expanded difference value from said difference signal.

Claim 7

The converter of claim 5, wherein said spatial expander means determines said spatially expanded difference value using a first spatial window when said edge detector means detects an edge and using a second spatial window when said edge detector detects no edge, said first spatial window having a smaller area than said second spatial window.

Claim 8

The converter of claim 1, further comprising: an edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and a spatial expander means for determining a spatially expanded difference value based on output of said edge detecting means and said video signal of said progressive format; and wherein said adaptive temporal filtering means determines said first and second temporal coefficient based on said spatially expanded difference value.

Claim 9

The converter of claim 4, further comprising: delay means for delaying said video signal of said progressive format for a first predetermined period; and a subtractor for subtracting output of said delay means from said video signal of said progressive format to obtain a difference signal; and wherein said spatial expander means determines said spatially expanded difference value from said difference signal.

Claim 10

The converter of claim 8, wherein said spatial expander means determines said spatially expanded difference value using a first spatial window when said edge detector means detects an edge and using a second spatial window when said edge detector detects no edge, said first spatial window having a smaller area than said second spatial window.

Claim 11

The converter of claim 1, further comprising: temporal expander means for temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value; and wherein said adaptive temporal filtering means temporally filters said video signal of said progressive format based on said temporally expanded difference value.

Claim 12

The converter of claim 10, further comprising: first delay means for delaying said video signal of said progressive format for a first predetermined period; first difference means for subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; and wherein said temporal expander means determines said temporally expanded difference value based on said difference value.

Claim 13

The converter of claim 11, wherein said temporal expander means comprises: feedback means for delaying said temporally expanded difference value for a second predetermined period, for subtracting a temporal expansion parameter from said delayed temporally expanded difference value, and for selecting one of a first constant and said delayed temporally expanded difference value as a feedback value based on said temporal expansion parameter; and selection means for selecting one of said difference value and said feedback value as said temporally expanded difference value.

Claim 14

The converter of claim 11, further comprising: edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; temporal expansion parameter determining means for determining a temporal expansion parameter based on output of said edge detecting means such that when an edge is detected a greater temporal expansion parameter is determined than when no edge is detected; and wherein said temporal expander means determines said temporally expanded difference value based on said temporal expansion parameter such that as a value of said temporal expansion parameter increases, said temporally expanded difference value decreases; and wherein said adaptive temporal filtering means performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 15

The converter of claim 1, further comprising: temporal expander means for detecting a degree of motion in an image represented by said video signal of said progressive format, and determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; and wherein said adaptive temporal filtering means performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 16

The converter of claim 14, wherein said adaptive temporal filter compares said temporally expanded difference value to a first and second threshold, said first threshold being less than said second threshold, performs a first degree of temporal filtering when said temporally expanded difference value is less than or equal to said first threshold, performs a second degree of temporal filtering when said temporally expanded difference value is less than said second threshold but greater than said first threshold, and performs a third degree of temporal filtering when said temporally expanded difference value being greater than or equal to said second threshold, said first degree being greater than said second degree, and said second degree is greater than said third degree.

Claim 17

The converter of claim 15, further comprising: edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and wherein said temporal adaptive filter determines said first and second threshold based on output of said edge detecting means such that said first and second thresholds are greater when an edge is detected than when no edge is detected.

Claim 18

The converter of claim 16, wherein said temporal adaptive filter includes a memory for storing different pairs of said first and second threshold which are addressed based on said output of said edge detecting means.

Claim 19

The converter of claim 1, further comprising: temporal expander means for detecting a degree of motion in an image represented by said video signal of said progressive format, and determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; and wherein said adaptive temporal filtering means performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, said first temporal coefficient increases and said second temporal coefficient decreases.

Claim 20

The converter of claim 1, further comprising: first delay means for delaying said video signal of said progressive format for a first predetermined period; first difference means for subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; temporal expander means for temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value, said temporal expander means including, feedback means for delaying said temporally expanded difference value for a second predetermined period, for subtracting a temporal expansion parameter from said delayed temporally expanded difference value, and for selecting one of a first constant and said delayed temporally expanded difference value as a feedback value based on said temporal expansion parameter, and selection means for selecting one of said difference value and said feedback value as said temporally expanded difference value; and wherein said adaptive temporal filtering means determines said first and second temporal coefficients based on said temporally expanded difference value.

Claim 21

The converter of claim 1, further comprising: temporal expander means for detecting a degree of motion in an image represented by said video signal of said progressive format, and determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and spatial expander means for spatially expanding said temporally expanded difference value based on output of said edge detecting means to obtain a spatially and temporally expanded difference value; and wherein said adaptive temporal filtering means performs said temporal filtering based on said spatially and temporally expanded difference value such that as said spatially and temporally expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 22

The converter of claim 1, further comprising: temporal expander means for temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value; and wherein edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and spatial expander means for spatially expanding said temporally expanded difference value to obtain a temporally and spatially expanded difference value based on output of said edge detecting means; and wherein said adaptive temporal filtering means temporally filters said video signal of said progressive format based on said temporally and spatially expanded difference value.

Claim 23

The converter of claim 1, further comprising: first delay means for delaying said video signal of said progressive format for a first predetermined period; first difference means for subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; temporal expander means for temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value, said temporal expander means including, feedback means for delaying said temporally expanded difference value for a second predetermined period, for subtracting a temporal expansion parameter from said delayed temporally expanded difference value, and for selecting one of a first constant and said delayed temporally expanded difference value as a feedback value based on said temporal expansion parameter, and selection means for selecting one of said difference value and said feedback value as said temporally expanded difference value; edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and spatial expander means for spatially expanding said temporally expanded difference value to obtain a temporally and spatially expanded difference value based on output of said edge detecting means; and wherein said adaptive temporal filtering means temporally filters said video signal of said progressive format based on said temporally and spatially expanded difference value.

Claim 24

The converter of claim 1, further comprising: temporal expander means for detecting a degree of motion in an image represented by said video signal of said progressive format, and determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; edge detecting means for detecting an edge in an image represented by said video signal of said progressive format; and spatial expander means for spatially expanding said temporally expanded difference value based on output of said edge detecting means to obtain a spatially and temporally expanded difference value; and wherein said adaptive filtering means determines said first and second temporal coefficients based on said temporally and spatially expanded difference value.

Claim 27

The method of claim 24, wherein said step (b) performs filtering between successive frames in said progressive format.

Claim 28

The method of claim 24, wherein said step (a) includes the steps of: (a1) changing a horizontal sample rate of each field of said video signal of said interlace format; and (a2) changing a number of lines of each field of said video signals of said interlace format.

Claim 29

The method of claim 24, further comprising: (c) detecting an edge in an image represented by said video signal of said progressive format; and (d) determining a spatially expanded difference value based on output of said step (c) and said video signal of said progressive format; and wherein said step (b) filters said video signal of said progressive format based on output of said step (d).

Claim 30

The method of claim 27, further comprising: (e) delaying said video signal of said progressive format for a predetermined period of time; and (f) subtracting output of said step (e) from said video signal of said progressive format to obtain a difference signal; and wherein said step (d) determines said spatially expanded difference value from said difference signal.

Claim 31

The method of claim 28, wherein said step (d) determines said spatially expanded difference value using a first spatial window when said edge detector means detects an edge and using a second spatial window when said edge detector detects no edge, said first spatial window having a smaller area than said second spatial window.

Claim 32

The method of claim 24, further comprising: (c) detecting an edge in an image represented by said video signal of said progressive format; and (d) determining a spatially expanded difference value based on output of said step (c) and said video signal of said progressive format; and wherein said step (b) determines said first and second temporal coefficient based on said spatially expanded difference value.

Claim 33

The method of claim 27, further comprising: (e) delaying said video signal of said progressive format for a first predetermined period; and (f) subtracting output of said step (e) from said video signal of said progressive format to obtain a difference signal; and wherein said step (d) determines said spatially expanded difference value from said difference signal.

Claim 34

The method of claim 31, wherein said step (d) determines said spatially expanded difference value using a first spatial window when said edge detector means detects an edge and using a second spatial window when said edge detector detects no edge, said first spatial window having a smaller area than said second spatial window.

Claim 35

The method of claim 24, further comprising: (c) temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value; and wherein said step (b) temporally filters said video signal of said progressive format based on said temporally expanded difference value.

Claim 36

The method of claim 33, further comprising: (d) delaying said video signal of said progressive format for a first predetermined period; (e) subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; and wherein said step (c) determines said temporally expanded difference value based on said difference value.

Claim 37

The method of claim 34, wherein said step (c) comprises the steps of: (C1) delaying said temporally expanded difference value for a second predetermined period; (C2) subtracting a temporal expansion parameter from output of said step (C1); (C3) selecting one of a first constant and output of said step (C2) as a feedback value based on said temporal expansion parameter; and (C4) selecting one of said difference value and said feedback value as said temporally expanded difference value.

Claim 38

The method of claim 34, further comprising: (f) detecting an edge in an image represented by said video signal of said progressive format; (g) determining a temporal expansion parameter based on output of said step (f) such that when an edge is detected a greater temporal expansion parameter is determined than when no edge is detected; and wherein said step (c) determines said temporally expanded difference value based on said temporal expansion parameter such that as a value of said temporal expansion parameter increases, said temporally expanded difference value decreases; and wherein said step (b) performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 39

The method of claim 24, further comprising: (c) detecting a degree of motion in an image represented by said video signal of said progressive format; (d) determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; and wherein said step (b) performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 40

The method of claim 37, wherein said step (b) comprises the steps of: (b1) comparing said temporally expanded difference value to a first and second threshold, said first threshold being less than said second threshold; (b2) performing a first degree of temporal filtering when said temporally expanded difference value is less than or equal to said first threshold; (b3) performing a second degree of temporal filtering when said temporally expanded difference value is less than said second threshold but greater than said first threshold; and performing a third degree of temporal filtering when said temporally expanded difference value being greater than or equal to said second threshold, said first degree being greater than said second degree, and said second degree is greater than said third degree.

Claim 41

The method of claim 38, further comprising: (e) detecting an edge in an image represented by said video signal of said progressive format; and wherein said step (b) determines said first and second threshold based on output of said step (e) such that said first and second thresholds are greater when an edge is detected than when no edge is detected.

Claim 42

The method of claim 39, wherein said step (b) includes the step of (b4) storing different pairs of said first and second threshold which are addressed based on said output of said step (e).

Claim 43

The method of claim 24 further comprising: (c) detecting a degree of motion in an image represented by said video signal of said progressive format; (d) determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; and wherein said step (b) performs said temporal filtering based on said temporal expanded difference value such that as said temporal expanded difference value increases, said first temporal coefficient increases and said second temporal coefficient decreases.

Claim 44

The method of claim 24, further comprising: (c) delaying said video signal of said progressive format for a first predetermined period; (d) subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; (e) temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value, said step (e) including the step of, (e1) delaying said temporally expanded difference value for a second predetermined period, (e2) subtracting a temporal expansion parameter from output of said step (e1), (e3) selecting one of a first constant and said output of said step (e2) as a feedback value based on said temporal expansion parameter, and (e4) selecting one of said difference value and said feedback value as said temporally expanded difference value; and wherein said step (b) determines said first and second temporal coefficients based on said temporally expanded difference value.

Claim 45

The method of claim 24, further comprising: (c) detecting a degree of motion in an image represented by said video signal of said progressive format; (d) determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; (e) detecting an edge in an image represented by said video signal of said progressive format; and (f) spatially expanding said temporally expanded difference value based on output of said step (e) to obtain a spatially and temporally expanded difference value; and wherein said step (b) performs said temporal filtering based on said spatially and temporally expanded difference value such that as said spatially and temporally expanded difference value increases, a lesser degree of temporal filtering is performed.

Claim 46

The method of claim 24, further comprising: (c) temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value; and wherein (d) detecting an edge in an image represented by said video signal of said progressive format; and (e) spatially expanding said temporally expanded difference value to obtain a temporally and spatially expanded difference value based on output of said step (d); and wherein said step (b) temporally filters said video signal of said progressive format based on said temporally and spatially expanded difference value.

Claim 47

The method of claim 24, further comprising: (c) delaying said video signal of said progressive format for a first predetermined period; (d) subtracting a pixel value of said delayed video signal of said progressive format from a pixel value of said video signal of said progressive format to obtain a difference value; (e) temporally expanding said video signal of said progressive format to obtain a temporally expanded difference value, said step (e) including the steps of, (e1) delaying said temporally expanded difference value for a second predetermined period, (e2) subtracting a temporal expansion parameter from output of said step (e1), (e3) selecting one of a first constant and said output of said step (e2) as a feedback value based on said temporal expansion parameter, and (e4) selecting one of said difference value and said feedback value as said temporally expanded difference value; (f) detecting an edge in an image represented by said video signal of said progressive format; and (g) spatially expanding said temporally expanded difference value to obtain a temporally and spatially expanded difference value based on output of said step (f); and wherein said step (b) temporally filters said video signal of said progressive format based on said temporally and spatially expanded difference value.

Claim 48

The method of claim 24, further comprising: (c) detecting a degree of motion in an image represented by said video signal of said progressive format; (d) determining a temporally expanded difference value based on said detected degree of motion such that as said detected degree of motion increases, said temporally expanded difference value increases; (e) detecting an edge in an image represented by said video signal of said progressive format; and (f) spatially expanding said temporally expanded difference value based on output of said step (e) to obtain a spatially and temporally expanded difference value; and wherein said step (b) determines said first and second temporal coefficients based on said temporally and spatially expanded difference value.