= YUV Plane Format = The YUV image as captured by the dog's camera is 208x160 full resolution pixels, but the underlying image has a higher resolution with less data per pixel. Colour information (U, V) is shared among pixels while intensity (Y) is at a higher res. We currently ignore the higher resolution Y values, only using those pixels about which we have full information. The underlying image is a 4:1:1 format, meaning 4 Y values, 1 U and 1 V value per macropixel (the Y plane is sampled at twice the resolution of the U and V planes) but we generally only use YLL as the Y value and ignore the others. What do YLL, YLH etc mean? I have no idea, but Jing's 2003 colour classifier code implies that they are positioned: YHH YHL?BR YLH YLL within a macropixel. The YUV image is stored as a series of rows of values, the Y row first, then U then V values for a row. When running offline (i.e. from saved YUV images) this sequence repeats so the image looks like: YYYYYYYY...?BR UUUUUUUU...?BR VVVVVVVV...?BR YYYYYYYY...?BR UUUUUUUU...?BR ...........?BR The actual data from the camera when running online has three more rows of information though - three more Y rows, so it looks more like YYYYYYYY...?BR UUUUUUUU...?BR VVVVVVVV...?BR YYYYYYYY...?BR YYYYYYYY...?BR YYYYYYYY...?BR YYYYYYYY...?BR UUUUUUUU...?BR ........... We ignore that extra data, and only process the one Y row per pixel row. See also [wiki:BflFileFormat BFL file format] - the classified YUV images, and http://www.fourcc.org/index.php?http%3A//www.fourcc.org/yuv.php for more than you wanted to know about YUV.