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>A still image file containing one frame of a video codec has been long theorized The I-frame encoding in MPEG-1 was basically identical to baseline JPEG. The
by m0dest 8y ago
>A still image file containing one frame of a video codec has been long theorized
The I-frame encoding in MPEG-1 was basically identical to baseline JPEG. The compressed frames can be losslessly converted to JPEG and vice-versa. So, in a sense, we were already there.
Reusing the I-frame compression from a video codec is the only strategy that makes sense for a lossy still image codec. Video codecs are where the major innovation is happening, with wide participation from every player in the industry, and a large part of the innovation has been around improving I-frame efficiency. They're being hardware optimized and baked into software implementations. And even when patents are involved, still image codecs are usually able to piggyback on the video codec licenses that are already on the device.
- ksec 8y agoIt is interesting that H.262 ( MPEG 2 ) > H.263 ( Divx ) > H.264 ( AVC ) > H.265 (HEVC ) That is 4 generation a video codec improvement, and yet as an image format, MPEG 1 based Jpeg is still doing very well compared to latest HEIF. I mean four generation of improvement and we only got 50% reduction at similar quality. Why is it still image don't scale down as well as video?
- niftich 8y agoBecause many of the gains of successive video codecs comes from finding more efficient ways of encoding motion, which is something you clearly can't exploit with stills.
- derf_ 8y agoBecause different things sitting next to each other in space are not as inherently predictable from each other as the same thing moving through time.