Rgb to yuv format conversion and inverse conversion method and circuit for depth packing and depacking

A circuit to convert a YUV format to a RGB format applied in depacking a depth frame, wherein one pixel in the YUV format includes Y luminance, U chrominance and V chrominance, and one pixel in the RGB format includes a R subpixel, a G subpixel and a B subpixel, the depth frame in YUV format include at least four adjacent pixels in one group and the Y luminance, U chrominance and V chrominance of each pixel are arranged in vertical, theses four pixels in each group includes a first pixel, a second pixel, a third pixel, and a fourth pixel, the first pixel is located adjacent to the second pixel and the third pixel, and the fourth pixel is also located adjacent to the second pixel and the third pixel, the circuit comprising:

• a pixel retrieving unit to retrieve four Y luminance values, one U chrominance value and one V chrominance value from the four pixels of the YUV format;
• and
• a pixel converting unit to obtain two R, two G and two B subpixel values of the RGB format according to the obtained four Y luminance values, one U-chrominance value and one V chrominance value,
• wherein, of four pixels in the RGB format, the R subpixel value of the first pixel in the RGB format are calculated according to the Y luminance value of the first pixel in the YUV format, the G subpixel value of the second pixel in the RGB format are calculated according to the Y luminance value of the second pixel in the YUV format, the G subpixel value of the third pixel in the RGB format are calculated according to the Y luminance value of the third pixel in the YUV format, and the B subpixel value of the fourth pixel in the RGB format are calculated according to the Y luminance value of the fourth pixel in the YUV format, the B subpixel value of the first pixel in the RGB format is calculated according to the U chrominance value of the first pixel in the YUV format and an average of the R subpixel value of the first pixel and the G subpixel value of the third pixel in the RGB format, the R subpixel value of the fourth pixel in the RGB format is calculated according to the V chrominance value of the first pixel in the YUV format and an average of the G subpixel value of the second pixel and the B subpixel value of the fourth pixel in the RGB format.

A method applied in depacking a depth frame to convert from YUV format to RGB format, wherein one pixel in the YUV format includes Y luminance, U chrominance and V chrominance, and one pixel in the RGB format includes R subpixel, G subpixel and B subpixel, the depth frame in YUV format include at least four adjacent pixels in one group, and the Y luminance, U chrominance and V chrominance of each pixel are arranged in vertical, theses four pixels in each group includes a first pixel, a second pixel, a third pixel, and a fourth pixel, the first pixel is located adjacent to the second pixel and the third pixel, and the fourth pixel is also located adjacent to the second pixel and the third pixel, the method comprising steps of:

• obtaining four Y luminance value, one U chrominance value and one V chrominance value from the four pixels of the YUV format;
• and
• obtaining two R, two G and two B subpixel values of the RGB format according to the obtained four Y luminance value, one U chrominance value and one V chrominance value,
• wherein, of four pixels in the RGB format, the R subpixel value of the first pixel in the RGB format are calculated according to the Y luminance value of the first pixel in the YUV format, the G subpixel value of the second pixel in the RGB format are calculated according to the Y luminance value of the second pixel in the YUV format, the G subpixel value of the third pixel in the RGB format are calculated according to the Y luminance value of the third pixel in the YUV format, and the B subpixel value of the fourth pixel in the RGB format are calculated according to the Y luminance value of the fourth pixel in the YUV format, the B subpixel value of the first pixel in the RGB format is calculated according to the U chrominance value of the first pixel in the YUV format and an average of the R subpixel value of the first pixel and the G subpixel value of the second pixel in the RGB format, the R subpixel value of the fourth pixel in the RGB format is calculated according to the V chrominance value of the first pixel in the YUV format and an average of the G subpixel value of the third pixel and the B subpixel value of the fourth pixel in the RGB format.

A circuit to convert a YUV format to a RGB format applied in depacking a depth frame, wherein one pixel in the YUV format includes Y luminance, U chrominance and V chrominance, and one pixel in the RGB format includes R subpixel, G subpixel and B subpixel, the depth frame in YUV format include at least four adjacent pixels in one group, and the Y luminance, U chrominance and V chrominance of each pixel are arranged in vertical, theses four pixels in each group includes a first pixel, a second pixel, a third pixel, and a fourth pixel, the first pixel is located adjacent to the second pixel and the third pixel, and the fourth pixel is also located adjacent to the second pixel and the third pixel, the circuit comprising:

• a pixel retrieving unit to retrieve four Y luminance value, one U chrominance value and one V chrominance value from the four pixels of the YUV format;
• and
• a pixel converting unit to obtain two R, two G and two B subpixel values of the RGB format according to the obtained four Y luminance value, one U chrominance value and one V chrominance value,
• wherein, of four pixels in the RGB format, the R subpixel value of the first pixel in the RGB format are calculated according to the Y luminance value of the first pixel in the YUV format, the G subpixel value of the second pixel in the RGB format are calculated according to the Y luminance value of the second pixel in the YUV format, the G subpixel value of the third pixel in the RGB format are calculated according to the Y luminance value of the third pixel in the YUV format, and the B subpixel value of the fourth pixel in the RGB format are calculated according to the Y luminance value of the fourth pixel in the YUV format, the B subpixel value of the first pixel in the RGB format is calculated according to the U chrominance value of the first pixel in the YUV format and an average of the R subpixel value of the first pixel and the G subpixel value of the second pixel in the RGB format, the R subpixel value of the fourth pixel in the RGB format is calculated according to the V chrominance value of the first pixel in the YUV format and an average of the G subpixel value of the third pixel and the B subpixel value of the fourth pixel in the RGB format.

A method applied in packing a depth frame to convert from RGB format to YUV format, wherein one pixel in the RGB format includes a R subpixel, a G subpixel and a B subpixels, and the one pixel in the YUV format includes Y luminance, U chrominance and V chrominance, the depth frame in RGB format include at least four adjacent pixels in one group, and the R subpixel, G subpixel and B subpixel of each pixel are arranged in vertical, these four pixels in each group includes a first pixel, a second pixel, a third pixel, and a fourth pixel, and the first pixel is located adjacent to the second pixel and the third pixel, and the fourth pixel is also located adjacent to the second pixel and the third pixel, the method comprises following steps of:

• obtaining two R, two G and two B subpixel values having interleaved positions from the four pixels of the RGB format;
• and
• obtaining four Y-luminance value, one U-chrominance value and one V-chrominance value of the YUV format according to the obtained two R, two G, and two B subpixel values,
• wherein, of four pixels in the YUV format, the Y luminance value of the first pixel in the YUV format are calculated according to the R subpixel value of the first pixel in the RGB format, the Y luminance value of the second pixel in the YUV format are calculated according to the G subpixel value of the second pixel in the RGB format, the Y luminance value of the third pixel in the YUV format are calculated according to the G subpixel value of the third pixel in the RGB format, and the Y luminance value of the fourth pixel in the YUV format are calculated according to the B subpixel value of the fourth pixel in the RGB format, the U chrominance value of the first pixel in the YUV format is calculated according to subtracting the B subpixel value of the first pixel in the RGB format to an average of the R subpixel value of the first pixel and the G subpixel value of the third pixel in the RGB format, the V-chrominance value of the first pixel in the YUV format is calculated according to subtracting the R subpixel value of the fourth pixel in the RGB format and an average of the G subpixel value of the second pixel and the B subpixel value of the fourth pixel in the RGB format.