search

johanneszab / TumblThree

A Tumblr Blog Backup Application
https://www.jzab.de/content/tumblthree
MIT License
922 stars 130 forks source link

Suggestion: Save images as JPG or PNG #246

Open EC-O-DE opened 6 years ago

EC-O-DE commented 6 years ago

Could there be option?

johanneszab commented 6 years ago

Sure, but I'm not sure if that makes sense. That requires to transcode the images from say png to jpg and either increase the file size or lose quality.

It's not much code to add for this feature. There is something in the .NET Framework already to save images in different formats.

EC-O-DE commented 6 years ago

OK. Hmm. When converting to JPG is 4:4:4 or 4:4:2 available? With 100% quality? Yes not lossless but significantly smaller than PNG. PNG should have "compression" of 9 - and interlaced.

untitled

Progressive "is a must" for JPG.

Hrxn commented 6 years ago

I don't get what you are trying to achieve here... johanneszab already described the issue with transcoding.

And you cannot change chroma subsampling of JPEG files post facto without quality loss and new issues like compression artifacts etc..

https://en.wikipedia.org/wiki/Generation_loss#Digital_generation_loss

EC-O-DE commented 6 years ago

Sure. I meant if a user opts-in for reduction. But then again there's many apps that does just that and nothing but that. Many even without options. Priorities, and this is not top issues I'm sure.