… for Codecs & Media

Tip #1192: What Are Compression Artifacts?

Larry Jordan – LarryJordan.com

Compression artifacts are blurry rectangles in a compressed image.

A source image (top) compared to an image with severe artifacts.

Topic $TipTopic

Compression artifacts are caused by a compression data rate that is too low. These are most often seen as blurry rectangles that randomly “crawl” around an image.

In this screen shot, the source image is on top. The compressed image, with severe artifacts, is on the bottom.

Look at the lost detail in their hair, the “stair-steppy” edges along both girl’s shoulders and ugly blotches throughout their skin.

Artifacts most often show up in regions of similar color – skin, hair, sky, sand…

These can only be removed by recompressing your video at a higher (faster) bit rate.


Please rate the helpfulness of this tip.

Click on a star to rate it!

3 Comments
  1. Oscar
    Oscar says:

    Thanks for the article! I’d like to add other artifacts could be color banding and blurriness if chroma subsampling and bit depth reduction is also utilized

    Reply
    • Larry Jordan
      Larry Jordan says:

      Loren:

      I don’t change the bit rate based on hardware vs. software or 1 or 2 pass.

      I could I guess, but I haven’t found it worth it.

      Larry

      Reply

Leave a Comment

Want to join the discussion?
Feel free to contribute!
All comments are moderated.

Leave a Reply

Your email address will not be published. Required fields are marked *