mozjpeg removes EXIF/ITPC data from PNG files

[robrwo]

I've run the mozjpeg build from the master branch, with PNG support enabled. It appears to remove IPTC data from PNG files.

[kornelski]

Yeah, the demo cjpeg command just copies the pixels out of input images. It's generally terrible all-around, so I recommend compiling ImageMagick with MozJPEG support, or using something more sophisticated like https://github.com/imazen/imageflow