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Suggesting an alternate way for XNView to handle camera-raw.

Posted: Sun May 04, 2014 11:08 pm
by Ben321
Instead of forcing conversion to 8-bits-per-channel mode, XNView should leave it in 16-bits-per-pixel grayscale mode and convert it to PNG (the only common image format that actually supports 16-bits-per-pixel or per-channel mode). This means also leaving its original Bayer pattern, and the end user of this PNG file would need to use other existing software (or write their own) to process the Bayer pattern that stores the color, in order to produce proper colored pixels.
However, the hardest step is getting the Bayer color array image, as most "raw" formats actually compress this data, using a very uncommon format called "lossess JPEG" (not the slightly more common lossless JPEG formats called JPEG2000 and JPEG-LS, but rather a quite rare format just called "lossless JPEG"), which most programs are incapable of decoding (including the one I'm trying to write). I need a program which has the capability of extracting the Bayer image, so that once that Bayer image is extracted, I can use the program I'm writing to decode (read as get the pixel colors from) the Bayer pattern, and also perform any additional steps I may want in processing. But since my program can't decompress the "lossless JPEG" format, I'm going to need a 3rd party program that can. And for that I'm turning to XNView, and can only hope that the guy who wrote XNView will sincerely consider my request to include a feature for exporting the decompressed image data (the raw Bayer image itself) as a 16-bits-per-pixel PNG image (I already have code for decompressing 16bpp PNG images available for use in my program).