Originally Posted by omegatron
You miss what I am saying
The medium threshold triggers a recompress based on image dimension. The width and height thresholds trigger a recompress based on the same. If your thresholds are high and the image is lower than your set thresholds then the image is basically just copied since ImageMagick does not really touch it. Thus as I explained above.
Thanks, Chuck. I think I understand what you're saying. You're right - if the image is lower than your dimension
thresholds, then the image will simply be copied. The software doesn't care how big the image is in KB, and that's my point.
If my maximum dimensions were set at 600x600
Someone uploads a JPG picture that is 600x600 and 650kb in size
the medium dimension limit is set at 400 so a medium images is created
The full size and compressed medium images are copied.
Now I'm transmitting a 60kb medium file and a 650kb full size file, Every user that clicks on the picture is sucking up 710k of bandwidth. That's the problem.
The 650kb image doesn't need to be 650kb. It can probably be re-compressed to 100k or less without dramatically affecting the image quality, and not changing the size from 600x600. But there's no image size (kb) threshold to trigger a recompress. Even with relatively low dimension thresholds, someone can still upload a big honkin' file
that's been download hundreds of times before I even notice.
I can either prevent users from uploading those images (with the kb upload limit), or I can live with people sucking up a ton of bandwidth. That doesn't make sense because GD2 and ImageMagick can both recompress the images without resizing them. In this scenario, the bandwidth difference would be 710k versus 160k.