Timeline for Should JPEG encoding take into account gamma?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 15, 2015 at 15:18 | vote | accept | Mokosha | ||
| Sep 15, 2015 at 2:23 | comment | added | v.oddou | The gamma exponent is stored in JPEG exif data. most software totally ignore it. but you can assume than after decoding a jpeg its already in gamma space so there is no conversion to do before sending the rgb value on the display buffer. | |
| Sep 11, 2015 at 8:22 | answer | added | Simon F | timeline score: 2 | |
| Aug 24, 2015 at 8:07 | comment | added | Simon F | "Video demystified" also says: "YCbCr is the color space originally defined by BT.601, and now used for all digital component video formats. .... The technically correct notation is Y'Cb'Cr' since all three components are derived from R'G'B'." | |
| Aug 24, 2015 at 7:54 | comment | added | Simon F | AFAIK, video standards assume R'G'B', ie. a non-linear colour space, when applying the 3x3 colour transforms to/from YCbCr. In an application such as video where one wants to maximise quality per bit, it doesn't make sense to use linear. I think sections 27 and 29 of Charles Poyton's Color FAQ express it more clearly: poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC27 | |
| Aug 23, 2015 at 4:25 | answer | added | Pseudonym | timeline score: 7 | |
| Aug 22, 2015 at 19:55 | comment | added | yuriks | I'm not posting this as an answer since I'm not confident in it, but human vision's perception of brightness is not linear. In fact, sRGB does a quite good job of compensating for that and giving the most precision in the areas that matter. So you might find that gamma correcting before compressing luma may actually yield worse results. | |
| Aug 22, 2015 at 12:27 | comment | added | joojaa | I dont know but it certainly does make sense not to gamma correct. | |
| Aug 22, 2015 at 8:13 | history | asked | Mokosha | CC BY-SA 3.0 |