Tip #1192: What Are Compression Artifacts?
… for Codecs & Media
Tip #1192: What Are Compression Artifacts?
Larry Jordan – LarryJordan.com
Compression artifacts are blurry rectangles in a compressed image.
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.
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
Higher but slower bitrate using “Faster” setting? Same question about 2-pass?
Best, as always,
Loren
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