3 ms·

I think we can agree that my 60 second test wasn't very scientific (nor was it meant to be), but I'm confident that the result is still typical of the type of s

by mthoms 16y ago

I think we can agree that my 60 second test wasn't very scientific (nor was it meant to be), but I'm confident that the result is still typical of the type of savings you'd see using a more controlled process. Since we're nitpicking, I might as well point out that you can't "cut out" portions of a jpeg either.

ars 16y ago
Actually you can. See the jpegtran command - it works losslessly on the DCT. If you do want to cut out the alpha region, do not trim right up to the image. Instead trim only in 16 pixel blocks. By having a sharp edge inside a macroblock you increase the storage requirements. No one has written it currently as far as I know, but it's also possible to selectively remove/replace 16x16 pixel blocks inside the jpeg losslessly.