Image Lossy Compression to Different Formats

0
votes

I have looked for this everywhere and already installed a few softwares that did not help me.

The thing is, I am studying and researching image and video quality analysis and part of the process is applying my work to different types of lossy compression formats.

Regarding the image part of the work, to do so for JPEG was the simplest thing. I was using something like this command line:

mogrify -format jpg -quality 15 img01.bmp

However, when I tried to move the study to other lossy compression formats, I could not find anything that allowed me to compress an image to different values of quality with a format that was not JPG. Just a few examples would be PGF, CPC, Fractual Compression etc.

It's important to say that Lossless Compression, such as PNG, won't help me.

I want to ask if anyone knows a software, a package or a library for python that allows me to compress an image to a lossy compression format (other that JPEG) and change the quality of it, even to the point of where the image is really terrible (5% quality on JPEG, for example).

Thank you very much for the help and attention.

1
pythoncompressionjpeg
TIFF and WebP can each be lossy. – Scott Hunter
Saving to GIF involves reducing the color palette, which is a lossy operation. You can often control the number of colors in the palette. – Mark Ransom

1 Answers

0
votes

There is no "quality" setting in JPEG. Some encoders use quality as a simplified interface method for selecting quantization tables. You mentioned PNG. You can control the compression settings. The difference is that in JPEG compression setting trade off variations from the original against the output stream size. In PNG the compression settings trade off the time to do the compression against the output stream size.

You are unlikely to find compression values analogous to encoder-specific quality settings among various compression formats.