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Lymphatus / CaesiumPH

Lossless JPEG compression for photographers and webmasters
http://saerasoft.com/caesium/ph
GNU General Public License v3.0
90 stars 11 forks source link

Progressive (Preferences) not working #7

Closed Voodoopupp closed 8 years ago

Voodoopupp commented 8 years ago

The progressive hook has no function. Even if it is not set, all images are progressive afterwards.

Voodoopupp commented 8 years ago

And there is another thing you have to take care of: now with #4 CaesiumPH will skip bigger images and replace them with the original ones.

But what if someone want to have progressive images in the end? If the filesize is bigger afterwards, he will not get a new file. Instead of this, he will have in the end a mixed up image folder with compressed (progressive) and non-compresses (baseline) images.

Therefore I think it must be this way: if the progressive hook is set, CaesiumPH must compress the image and save it, even if the file size will be increased. There should be an information on the hook like "if set, images can increase in size"

Lymphatus commented 8 years ago

The fix is in 83470c2f940b72d13afe48147cb5462a14543aee

About the progressive images and file size increase, I'm not really convinced by your solution. CaesiumPH is an image compressor and not an image converter from baseline to progressive or vice versa. You can choose to output a progressive image because it's usually smaller and because there's still no 100% support for progressive JPEGs from decoders, just that. I want to keep very clear for the users this is a tool designed just to compress images.

So, right now, I think I will leave the compression flow the same, so you won't get a progressive/baseline output if it's bigger than the original in any case.

However I will keep track of this if it starts to became an issue for multiple users.