MbufBayer

This function converts a single-band, Bayer color-encoded image into a 1- or 3-band image. When using a single-band buffer as the destination, the destination will be filled with the Y-component obtained from the RGB to Y conversion when the Bayer image is decoded.

Optionally, you can specify to perform gamma correction and/or white balance correction on the image if the appropriate exponents and coefficients are provided, respectively. First, gamma correction is applied to the raw RGB values of the Bayer color-encoded image. Second, white balance correction is performed on the gamma corrected RGB values. Third, the demosaicing process converts the single-band, Bayer color-encoded image to a 1- or 3-band image. Finally, color correction is performed if M_COLOR_CORRECTION is specified. Color correction can only be used with the M_ADAPTIVE algorithm.

Note that you can use MbufBayer() to automatically calculate the appropriate white balance correction coefficients. To do so, specify a Bayer color-encoded source image that in reality should be a uniform shade of gray that is not too saturated, and add M_WHITE_BALANCE_CALCULATE to the ControlFlag parameter. After converting the image and calculating the appropriate coefficients, the coefficients are written to the specified MIL array buffer and the converted image is then corrected using these automatically calculated coefficients. Alternatively, you could fill an array with custom values, and then load these values (in order) into the MIL array using MbufPut1d() or MbufPut2d(). For more information, see the Correcting the white balance of your Bayer images subsection of the Using images acquired with a Bayer color filter section of Chapter 19: Data buffers. Ensure that the image was grabbed under the same lighting conditions as subsequent source images.

Note that you cannot calculate the white balance coefficients and specify an adaptive demosaicing in the same call to MbufBayer().

For more information on Bayer color-encoded images, the conversion, and the actual equations used to perform white balance and gamma correction, see the Using images acquired with a Bayer color filter section of Chapter 19: Data buffers.

Note that if the scale of the image is changed (using MdigControl() with M_GRAB_SCALE...) to a value other than 1 prior to grabbing a Bayer image, the Bayer image will not be converted properly; some of the Bayer pattern is lost during the scaling process, rendering color recovery impossible.