• 0 Posts
  • 18 Comments
Joined 1 year ago
cake
Cake day: July 14th, 2023

help-circle
  • It seems that we focus our interest in two different parts of the problem.

    Finding the most optimal way to classify which images are best compressed in bulk is an interesting problem in itself. In this particular problem the person asking it had already picked out similar images by hand and they can be identified by their timestamp for optimizing a comparison of similarity. What I wanted to find out was how well the similar images can be compressed with various methods and codecs with minimal loss of quality. My goal was not to use it as a method to classify the images. It was simply to examine how well the compression stage would work with various methods.



  • I was not talking about classification. What I was talking about was a simple probe at how well a collage of similar images compares in compressed size to the images individually. The hypothesis is that a compression codec would compress images with similar colordistribution in a spritesheet better than if it encode each image individually. I don’t know, the savings might be neglible, but I’d assume that there was something to gain at least for some compression codecs. I doubt doing deduplication post compression has much to gain.

    I think you’re overthinking the classification task. These images are very similar and I think comparing the color distribution would be adequate. It would of course be interesting to compare the different methods :)
















  • I build a lot of tools like that and the first thing I do is to go to the developer tool in my browser and observe the network traffic. When you find the resource you’re after you scroll back and see what requests resulted in that URL. Going from those requests you figure out in the original static HTML document and resource, which parameters are used for the construction of the URL, that might require reversing some javascript, but that’s rare. After that you’ll have a pretty good idea how you obtain the video resource from the original URL. Beware of cookie set by the requests, they might be needed to access the next requests. For building my tools I use Perl or sometimes just Bash or a GreaseMonkey userscript to fetch and parse the urls and construct the desired output.