Notebook · Field note
Never return a bigger file
A field note from Compresso about a promise small enough to test.
Draft for review
Some images are already well compressed. Run them through a compressor and they can come out larger than they went in. Most tools hand that bigger file back anyway.
Compresso makes one promise instead: it will never return a bigger file than it was given. If compression would grow an image, you get the original back.
A promise is only real if something fails without it, so a regression test pins it. If a change ever lets a bigger file through, the build goes red before anyone sees it.
The same rule shapes how I write about the library. I publish one measured run, 3.3 MB to 93.5 KB, and call it one run. Not an average, not a best case. The claim is exactly as big as the evidence.