Supported by...


Most PL-B600 and PL-B700 series cameras support 10 bit bit-depth. The PL-B777 and PL-B778 support 12 bit bit-depth.


PL-B800 and PL-B900 series cameras support 12 bit bit-depth.


The PL-D721, PL-D721P, PL-D722, PL-D725, PL-D726, PL-D729, PL-D732, and PL-D734 support 10 bit bit-depth.


The PL-D752, PL-D755, PL-D759, PL-D7512, PL-D795, PL-D799, PL-D7912, PL-D7715, and PL-D775 support 12 bit bit-depth.


Description


The number of bits used to represent the pixel value can be controlled.  Most applications will never need more than 8 bits.  A few applications, however, require more dynamic range.  


The camera always uses the highest number of bits internally.  For example, for a 10-bit camera, the analog image data from the sensor is digitized to 10-bits prior to image processing in the camera electronics.  The entire image processing chain, that is FFC, color correction, pixel addressing, lookup table, is performed at 10-bits.  The output of the image processing chain is where the user can select either the maximum available or truncated 8 bits.


The output bit depth is controlled using the PIXEL_FORMAT feature.  The output can be selected as MONO8 or MONO16 for a monochrome camera.  For color cameras, RGB24 is a simple example where three colors have 8 bits each.  YUV422, on the other hand, encodes the three colors into sixteen bits. See PIXEL_FORMAT for more information.  If the pixel format is set to maximize the bit depth, the bit data is padded with zeros in the least significant bits to create 16-bit words.  Hence, compared to the 8-bit formats, the 16-bit formats require twice the bandwidth on the interface and will result in a drop in frame rate for a given ROI.  


Since the user only selects the bit depth at the output stage, the look-up table or gamma can be used to expand or compress the dynamic range as required at the high bit-depth with the minimum loss of data and without impacting the frame rate.


API Control


The output bit depth is controlled using the PIXEL_FORMAT feature of the API.  The camera will output the maximum possible number of bits per pixel given the constraints of the pixel format selected.  For example, a CCD capable of 12-bit will truncate its output to 8 bits when a pixel format of MONO8 is selected.  If MONO16 is selected, the full 12-bits will be the output.


To determine the maximum number of bits used internally on-board the camera, see the MAX PIXEL SIZE feature of the API.