This is a very top level question with no code examples attached. I have an interest in using Mathematica to read raw files coming from a Canon camera, before they are converted into jpg's, where data is lost. Are there any existing non proprietary mathematica scripts, which can read a CR2 file from a Canon camera and display its image as it would if a jpeg were imported. At the very least a script that can display data about the image stored in the CR2 file to include intensity, size, pixel value, LRGB histograms, etc...
Yes! I have done this before with RAW files.
dcraw command line utility and convert the RAW file to a TIFF. You'll need to use appropriate command line options to prevent any processing of the data.
dcraw -o 0 -D -T -6 infile.cr2
It'll output a TIFF file with un-demosaiced raw sensor data. You can read that with Mathematica.
EXIF data can be extracted using
What I don't have a solution for yet is how to put any (Mathematica-processed) data back into RAW files (say, DNG) so it can be read into a RAW converter.