Returns the output file extension for a given image format is needed because the mozjpeg compressor needs to be saved with the jpg extension and to avoid the jpeg extension being added to the output file when saving a jpeg file
The image format
The original file extension
The output file extension
Returns the output file extension for a given image format is needed because the mozjpeg compressor needs to be saved with the jpg extension and to avoid the jpeg extension being added to the output file when saving a jpeg file