| It's great you listen. So I'll try. 1. Scaling down in linear colorspace is essential. One example is [1], where [2] is sRGB and [3] is linear. There are some canary images too [4]. 2. Plain bicubic filtering is not good anymore. EWA (Elliptical Weighted Averaging) filtering by Nicolas Robidoux produces much better results [5]. 3. Using default JPEG quantization tables at quality 75 is not good anymore. That's what people referring as horrible compression. MozJPEG [6] is a much better alternative. With edge detection and quality assessment, it's even better. 4. You have to realize that 8-bit wide-gamut photographs will show noticeable banding on sRGB devices. Here's my attempt [7] to reveal the issue using sRGB as a wider gamut colorspace. [1] https://unsplash.com/photos/UyUvM0xcqMA [2] https://cloud.githubusercontent.com/assets/107935/13997633/a... [3] https://cloud.githubusercontent.com/assets/107935/13997660/b... [4] https://cloud.githubusercontent.com/assets/72159/11488537/3d... [5] http://www.imagemagick.org/Usage/filter/nicolas/ [6] https://github.com/mozilla/mozjpeg [7] https://twitter.com/vmdanilov/status/745321798309412865 |
