Set image quality

[koertho]

Sometimes the thumbsnail generated with this library have a bigger file size then the original files, even when they have a bigger resolution. The problem is, that the generated images (jpg) have always 100% image quality. It would be great to set the file quality in the parameter or the library should use the quality of the original image.

[koertho]

I've integrated this feature in my fork (just for jpeg). Can do a pull request, if you want (I never did this before).

[jamiebicknell]

I've never been keen on having a query string option that only applies one particular file format, but I do agree that the quality should be able to be customised somewhere. Instead I think it's best if the quality was configured as a constant and same for each instance.

View commit here: 0930eea

[koertho]

That's perfect. Thank you!

[jamiebicknell]

The constant is my preference as I feel the quality wouldn't change on a per image basis, but more or a per install/instance basis. If you do use you're query string version, don't forgot to also add the quality option to the $file_hash variable.