Method and apparatus for processing video pictures for improving picture quality for subsequent display
View Patent ↗The invention relates to a method for processing data of video pictures for displaying the pictures on a display device like a Plasma Display Panel. The existing false contour effect compensation methods which make a false contour compensation based on shifting sub-field code word entries along the direction of the motion vector of a current pixel, produce an artifact in the pictures, in case of object crossings. In the appearing area there is a lack of light generation. The invention solves this problem by checking whether an area exists in the picture which is currently hidden but will appear in a next frame and providing an adapted compensation method for “hole filling”. The invention also gives a solution for an improved compensation method which is based on a dragging of sub-field code word entries along a motion vector direction to a current pixel.
1. Method for processing video pictures, e.g., the video pictures consisting of pixels, the pixels being digitally coded with at least one digital code words, wherein to each bit of a digital code word a certain duration is assigned, hereinafter called sub-field, during which the whole pixel or a component of the pixel is activated, wherein a motion vector is calculated for a pixel, and the motion vector is used for updating the at least one sub-field code word of the pixel for picture quality improvement, the method comprising the steps of: checking in the current picture whether there is an area which is currently hidden but appears in a next video picture; and updating the sub-field code words of pixels from the appearing area in the current picture by utilizing sub-field code word entries of pixels from the appeared area in a next video picture.
2. Method according to claim 1 , wherein the updating of the sub-field code words based on the motion vector is done by calculating shift coordinates for sub-field code word entries in dependence of the motion vector, wherein the motion vector is defined to point to the place, where a pixel in a current video picture moves to in a next video picture, and the shift coordinates are used for shifting sub-field code word entries of a current pixel to pixels along the motion vector direction.
3. Method according to claim 2 , further comprising a step of updating the sub-field code words of the pixels from the appearing area in the current picture by taking over sub-field code word entries of corresponding pixels from the appeared area in a next video picture.
4. Method according to claim 1 , wherein the updating of the sub-field code words for the pixels of the current video picture based on their motion vectors is done by calculating drag coordinates for sub-field code word entries in dependence of the motion vector, wherein the motion vector is defined to point to the place, where a pixel in a current video picture is coming from in a previous video picture, and the drag coordinates are used for dragging sub-field code word entries of pixels in the current video picture along the motion vector direction to the current pixel.
5. Method according to claim 4 , further comprising a step of compensating the sub-field code words of the pixels from the appearing area in the current picture by dragging sub-field code word entries of corresponding pixels in a next video picture along the motion vector direction to the current pixel.
6. Method according to claim 1 , further comprising analyzing whether, for pixels located en the mirror transformed motion vector arrow of the current pixel, motion vectors are assigned, which do not have a similarity with the motion vector of the current pixel for checking whether a current pixel belongs to an area which is currently hidden but appears in a next video picture.
7. Apparatus for processing video pictures, the video pictures consisting of pixels the pixels being digitally coded with at least one digital cede word, wherein to each bit of a digital cede word a certain duration is assigned, hereinafter called sub-field, during which the whole pixel or a component of the pixel is activated, wherein the apparatus comprises a motion estimation unit in which a motion vector is calculated for a pixel, wherein the apparatus further comprises a processing unit in which the motion vector is used for updating the at least one sub-field code word of the pixel for picture quality improvement, wherein the apparatus further comprises an appearing area detector which is adapted to check in the current picture whether there is an area which is currently hidden but appears in a next video picture, and wherein the apparatus comprises a compensating unit in which the sub-field code words of pixels from the appearing area in the current picture are compensated by utilizing sub-field code word entries of pixels from the appeared area in a next video picture.
8. Apparatus according to claim 7 , wherein the appearing area detector is integrated in the motion estimator.
9. Apparatus according to claim 7 , wherein the appearing area detector is a separate unit, which receives as an input the motion vectors of a current video picture.
10. Apparatus according to claim 7 , the apparatus comprising a matrix display, such as plasma display, LCOS display or DMD display.