如何压缩一批图像？

Question

We are constantly transferring gigabytes of compressed Tiffs overseas and it takes a long time for each batch of images to transfer. It is not uncommon for a batch to take over 6 hours to transfer. I would like to reduce the time to transfer a batch of images.

I understand that videos compress really well because most of the time each frame is generally very similar to the one before it and compression algorithms take advantage of that. In our scenario, the images often look similar to one another. Are there any image compression libraries I can use to take advantage of the fact that there is a lot of redundancy across images? Ideally I would want lossless compression.

Would it work if I turned the images into a video before transferring them and then turned them back to images on the other side? If this would work, what libraries would you recommend? I need to be able to call this from Java and preferably run it on Linux, but the library does not need to be written in Java. Windows could also be a possibility.

Answer 1

What I would try first:

Start from uncompressed tiffs (otherwise, it will be hard to find similarities).

tar them together (so they are contained within a single file, can be a specific range of images off course).

Then use a compression algorithm of your choice to see which one yields the best results (on the single file).

Easy enough to try out without much effort. How well it works depends on the source images themselves (and the compression algorithm used).

Alternative approach if the above does not yield enough results:

1. Make sure you have all uncompressed images.

2. Send over the first image.

3. Do a binary diff (or maybe diffing the hexdump) towards the next image.

4. Send over the diff file and apply it at the receiving end to reconstruct the image.

5. Repeat 3-4 for every image.

I personally don't think you will easily get good (lossless) results by using video compression algorithms (after all, they are specifically tailored to a different purpose).