Motion detection device and method, luminance/chrominance signal separation device and method, noise reduction device and method, and video display device and method

Abstract

The motion detection device includes an oblique correlation detection section, a motion detection section and a motion determination section. The oblique correlation detection section detects a correlation in an oblique direction (oblique correlation) of a composite video signal. The motion detection section detects a motion amount based on an inter-frame difference of the composite video signal. The motion determination section determines the presence/absence of a motion in the composite video signal based on the motion amount detected by the motion detection section. The motion determination section determines the presence/absence of the motion considering the detection results of the oblique correlation by the oblique correlation detection section.

1 . A motion detection device comprising: 
 an oblique correlation detection section for detecting an oblique correlation of a composite video signal;    a motion detection section for detecting a motion amount based on an inter-frame difference of the composite video signal; and    a motion determination section for determining the presence of a motion in the composite video signal based on the motion amount detected by the motion detection section,    wherein the motion determination section determines the presence of a motion considering the detection results of the oblique correlation obtained by the oblique correlation detection section.    
     
     
         2 . The motion detection device of  claim 1 , wherein the motion determination section determines the presence of a motion by setting a threshold of a level corresponding to the detection results of the oblique correlation obtained by the oblique correlation detection section and comparing the motion amount detected by the motion detection section with the threshold.  
     
     
         3 . The motion detection device of  claim 1 , wherein the motion determination section determines the presence of a motion by correcting the motion amount detected by the motion detection section according to the detection results of the oblique correlation obtained by the oblique correlation detection section and comparing the corrected motion amount with a predetermined threshold.  
     
     
         4 . The motion detection device of  claim 1 , wherein the motion determination section determines that “there is a motion” if the motion amount detected by the motion detection section is greater than a predetermined threshold, and determines the presence of a motion according to the detection results of the oblique correlation obtained by the oblique correlation detection section if the motion amount is smaller than the predetermined threshold.  
     
     
         5 . The motion detection device of  claim 1 , wherein the motion detection section comprises: 
 a first motion detection circuit for detecting a motion amount based on a one-frame difference of the composite video signal; and    a second motion detection circuit for detecting a motion amount based on a two-frame difference of the composite video signal.    
     
     
         6 . The motion detection device of  claim 1 , wherein the motion detection section comprises: 
 a first motion detection circuit for detecting a motion amount based on a one-frame difference of a luminance signal extracted from the composite video signal by luminance/chrominance signal separation using line correlation; and    a second motion detection circuit for detecting a motion amount based on a one-frame difference of a chrominance signal extracted from the composite video signal by luminance/chrominance signal separation using line correlation.    
     
     
         7 . The motion detection device of  claim 5 , wherein the motion determination section comprises: 
 a first motion determination circuit for determining the presence of a motion in the composite video signal based on the motion amount detected by the first motion detection circuit; and    a second motion determination circuit for determining the presence of a motion in the composite video signal based on the motion amount detected by the second motion detection circuit.    
     
     
         8 . The motion detection device of  claim 7 , wherein the first and/or second motion determination circuit determines the presence of a motion considering the determination results of the oblique correlation obtained by the oblique correlation detection section.  
     
     
         9 . The motion detection device of  claim 6 , wherein the motion determination section comprises: 
 a first motion determination circuit for determining the presence of a motion in the composite video signal based on the motion amount detected by the first motion detection circuit; and    a second motion determination circuit for determining the presence of a motion in the composite video signal based on the motion amount detected by the second motion detection circuit.    
     
     
         10 . The motion detection device of  claim 9 , wherein the first and/or second motion determination circuit determines the presence of a motion considering the determination results of the oblique correlation obtained by the oblique correlation detection section.  
     
     
         11 . The motion detection device of  claim 5  wherein the motion determination section switches between first determination and second determination according to the detection results of the oblique correlation obtained by the oblique correlation detection section, 
 the first determination comprises determining the presence of a motion based on the motion amount detected by the first detection circuit, and    the second determination comprises determining the presence of a motion based on the motion amount detected by the first motion detection circuit and the motion amount detected by the second motion detection circuit.    
     
     
         12 . The motion detection device of  claim 6 , wherein the motion determination section switches between first determination and second determination according to the detection results of the oblique correlation obtained by the oblique correlation detection section, 
 the first determination comprises determining the presence of a motion based on the motion amount detected by the first detection circuit, and    the second determination comprises determining the presence of a motion based on the motion amount detected by the first motion detection circuit and the motion amount detected by the second motion detection circuit.    
     
     
         13 . A luminance/chrominance signal separation device comprising: 
 a first luminance/chrominance signal separation section for extracting a first luminance signal and a first chrominance signal from a composite video signal using line correlation;    a second luminance/chrominance signal separation section for extracting a second luminance signal and a second chrominance signal from the composite video signal using frame correlation;    the motion detection device of  claim 1;  and    a switch section for combining the first and second luminance signals together according to the determination results from the motion determination section of the motion detection device and outputting the combined signal as a third luminance signal, and combining the first and second chrominance signals according to the determination results from the motion determination section of the motion detection device and outputting the combined signal as a third chrominance signal.    
     
     
         14 . A luminance/chrominance signal separation device comprising: 
 a first luminance/chrominance signal separation section for extracting a first luminance signal and a first chrominance signal using line correlation in the current frame of a composite video signal;    a second luminance/chrominance signal separation section for extracting a second luminance signal and a second chrominance signal using line correlation in the preceding frame of the composite video signal;    the motion detection device of  claim 6;  and    a switch section for combining the first and second luminance signals together according to the determination results from the motion determination section of the motion detection device and outputting the combined signal as a third luminance signal, and combining the first and second chrominance signals according to the determination results from the motion determination section of the motion detection device and outputting the combined signal as a third chrominance signal.    
     
     
         15 . A noise reduction device comprising: 
 a first noise reduction section for reducing noise in a composite video signal using line correlation;    a second noise reduction section for reducing noise in the composite video signal using frame correlation;    the motion detection device of  claim 1;  and    a switch section for combining a video signal obtained from the first noise reduction section and a video signal obtained from the second noise reduction section according to the determination results from the motion determination section of the motion detection device and outputting the combined signal.    
     
     
         16 . A motion detection method comprising the steps of: 
 (a) detecting an oblique correlation of a composite video signal;    (b) detecting a motion amount based on an inter-frame difference of the composite video signal; and    (c) determining the presence of a motion in the composite video signal based on the motion amount detected in the step (b),    wherein in the step (c), the presence of a motion is determined considering the detection results of the oblique correlation obtained in the step (a).    
     
     
         17 . The motion detection method of  claim 16 , wherein in the step (c), the presence of a motion is determined by setting a threshold of a level corresponding to the detection results of the oblique correlation obtained in the step (a) and comparing the motion amount detected in the step (b) with the threshold.  
     
     
         18 . The motion detection method of  claim 16 , wherein in the step (c), the presence of a motion is determined by correcting the motion amount detected in the step (b) according to the detection results obtained in the step (a) and comparing the corrected motion amount with a predetermined threshold.  
     
     
         19 . The motion detection method of  claim 16 , wherein in the step (c), it is determined that “there is a motion” if the motion amount detected in the step (b) is greater than a predetermined threshold, and the presence of a motion is determined according to the detection results of the oblique correlation obtained in the step (a) if the motion amount is smaller than the predetermined threshold.  
     
     
         20 . The motion detection method of  claim 16 , wherein the step (b) comprises the steps of: 
 (d) detecting a motion amount based on a one-frame difference of the composite video signal; and    (e) detecting a motion amount based on a two-frame difference of the composite video signal.    
     
     
         21 . The motion detection method of  claim 16 , wherein the step (b) comprises the steps of: 
 (d) detecting a motion amount based on a one-frame difference of a luminance signal extracted from the composite video signal by luminance/chrominance signal separation using line correlation; and    (e) detecting a motion amount based on a one-frame difference of a chrominance signal extracted from the composite video signal by luminance/chrominance signal separation using line correlation.    
     
     
         22 . The motion detection method of  claim 20 , wherein the step (c) comprises the steps of: 
 (f) determining the presence of a motion in the composite video signal based on the motion amount detected in the step (d); and    (g) determining the presence of a motion in the composite video signal based on the motion amount detected in the step (e).    
     
     
         23 . The motion detection method of  claim 22 , wherein the in the step (f) and/or step (g), the presence of a motion is determined considering the detection results of the oblique correlation obtained in the step (a).  
     
     
         24 . The motion detection method of  claim 21 , wherein the step (c) comprises the steps of: 
 (f) determining the presence of a motion in the composite video signal based on the motion amount detected in the step (d); and    (g) determining the presence of a motion in the composite video signal based on the motion amount detected in the step (e).    
     
     
         25 . The motion detection method of  claim 24 , wherein the in the step (f) and/or step (g), the presence of the motion is determined considering the detection results of the oblique correlation obtained in the step (a).  
     
     
         26 . The motion detection method of  claim 20 , wherein in the step (c), switching is made between first determination and second determination according to the detection results of the oblique correlation obtained in the step (a), 
 the first determination comprises determining the presence of a motion based on the motion amount detected in the step (d), and    the second determination comprises determining the presence of a motion based on the motion amount detected in the step (d) and the motion amount detected in the step (e).    
     
     
         27 . The motion detection method of  claim 21 , wherein in the step (c), switching is made between first determination and second determination according to the detection results of the oblique correlation obtained in the step (a), 
 the first determination comprises determining the presence of a motion based on the motion amount detected in the step (d), and    the second determination comprises determining the presence of a motion based on the motion amount detected in the step (d) and the motion amount detected in the step (e).    
     
     
         28 . A luminance/chrominance signal separation method comprising the steps of: 
 (h) extracting a first luminance signal and a first chrominance signal from a composite video signal using line correlation;    (i) extracting a second luminance signal and a second chrominance signal from the composite video signal using frame correlation;    the motion detection method of  claim 16;  and    (j) combining the first and second luminance signals according to the determination results in the step (c) of the motion detection method and outputting the combined signal as a third luminance signal, and combining the first and second chrominance signals according to the determination results in the step (c) of the motion detection method and outputting the combined signal as a third chrominance signal.    
     
     
         29 . A luminance/chrominance signal separation method comprising the steps of: 
 (k) extracting a first luminance signal and a first chrominance signal using line correlation in the current frame of a composite video signal;    (l) extracting a second luminance signal and a second chrominance signal using line correlation in the preceding frame of the composite video signal;    the motion detection method of  claim 21;  and    (m) combining the first and second luminance signals according to the determination results in the step (c) of the motion detection method and outputting the combined signal as a third luminance signal, and combining the first and second chrominance signals according to the determination results in the step (c) of the motion detection method and outputting the combined signal as a third chrominance signal.    
     
     
         30 . A noise reduction method comprising the steps of: 
 (n) reducing noise in a composite video signal using line correlation;    (o) reducing noise in the composite video signal using frame correlation;    the motion detection method of  claim 16;  and    (p) combining a video signal obtained in the step (n) and a video signal obtained in the step (o) according to the determination results in the step (c) of the motion detection method and outputting the combined signal.    
     
     
         31 . A video display device comprising either one of the motion detection device of  claim 1 , the luminance/chrominance signal separation device of  claim 13  and the noise reduction device of  claim 15 .  
     
     
         32 . A video display device comprising either one of the motion detection device of  claim 1 , the luminance/chrominance signal separation device of  claim 14  and the noise reduction device of  claim 15 .  
     
     
         33 . A video display method comprising either one of the motion detection method of  claim 16 , the luminance/chrominance signal separation method of  claim 28  and the noise reduction method of  claim 30 .  
     
     
         34 . A video display method comprising either one of the motion detection method of  claim 16 , the luminance/chrominance signal separation method of  claim 29  and the noise reduction method of  claim 30.