ProcessedImage has a white border - How are MicronsPerPixel defined?

[TheChrizZly]

Hello, I do get the processed image with the CusNewProcessedImageFn callback. from the imageinfo I get the information that the image size is 640x480. However. Analysing the data, the first and last 22 columns do have the RGBA values: 0,0,0,0, which results in a real image size of 596x480.

a) Can this observation be correct or is there an error in my implementation?

b) How are the micronsPerPixel calculated? On a 640x480 image or on the "real" 596x480 image?

Kind regards, Christian