3 ms·

As someone who hosts images on their site, what is the best software (preferably open source) one can use to compress JPEG images imported from a digital camera

As someone who hosts images on their site, what is the best software (preferably open source) one can use to compress JPEG images imported from a digital camera? I would be glad to serve only JPEGs and dispense with WebP versions and simplify my site html. A straightforward encoding of a JPEG into a WebP (using GIMP) does give me an almost 1/3rd reduction in file size, which is not insignificant.

singlow 6y ago
ImageMagick
zimpenfish 6y ago
imager.io was on here recently and seems to do a good job compressing into normal JPEG images. https://github.com/imager-io/imager https://github.com/imager-io/imager
theandrewbailey 6y ago
When you convert JPEG to WebP, you're converting data in a lossy format to another lossy format. Of course you're going to get good JPEG to WebP compression, because you're starting with a low-quality source. If you start with a lossless image (RAW/PNG/TIFF/etc.) instead of a JPEG, you might get different results.
acdha 6y ago
Re-encoding will produce smaller images because it’s discarding information - if you compare that WebP image you the original you’ll inevitably see fine detail is missing. That may or may not be reasonable but to be fair you’d want to compare it with different quality levels using MozJPEG. The easiest way to do a simple comparison might be to install ImageOptim and process a few images with various tools. Based on that you could put the same tools into your site’s workflow.
tyingq 6y ago
Others have mentioned you're using 2 lossy formats. You would probably get a similar end file size with jpegoptim. Compile it with mozjpeg for even smaller sizes.
- singlow 6y ago
  Not sure about his images, but WebP supports lossless compression. If they are coming from a camera, it seems reasonable that they might be lossless, depending on the camera settings. [Update] Just noticed he's going JPEG->WebP so my comment makes no sense.
lmm 6y ago
Just going by elsewhere in the thread, if you want to not lose any quality then brunsli / Jpeg XL sounds like the way to go.

singlow 6y ago

ImageMagick

zimpenfish 6y ago

imager.io was on here recently and seems to do a good job compressing into normal JPEG images. https://github.com/imager-io/imager https://github.com/imager-io/imager

theandrewbailey 6y ago

When you convert JPEG to WebP, you're converting data in a lossy format to another lossy format. Of course you're going to get good JPEG to WebP compression, because you're starting with a low-quality source. If you start with a lossless image (RAW/PNG/TIFF/etc.) instead of a JPEG, you might get different results.

acdha 6y ago

Re-encoding will produce smaller images because it’s discarding information - if you compare that WebP image you the original you’ll inevitably see fine detail is missing. That may or may not be reasonable but to be fair you’d want to compare it with different quality levels using MozJPEG. The easiest way to do a simple comparison might be to install ImageOptim and process a few images with various tools. Based on that you could put the same tools into your site’s workflow.

tyingq 6y ago

Others have mentioned you're using 2 lossy formats. You would probably get a similar end file size with jpegoptim. Compile it with mozjpeg for even smaller sizes.

singlow 6y ago
Not sure about his images, but WebP supports lossless compression. If they are coming from a camera, it seems reasonable that they might be lossless, depending on the camera settings. [Update] Just noticed he's going JPEG->WebP so my comment makes no sense.

lmm 6y ago

Just going by elsewhere in the thread, if you want to not lose any quality then brunsli / Jpeg XL sounds like the way to go.