Timeline for Gamma correction and halftone
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 28, 2018 at 11:08 | comment | added | joojaa | @Wyck a typical display is non calibrated. | |
| Feb 27, 2018 at 8:46 | comment | added | Simon F | Given that you are only doing half-toning, you could probably get away with a much cheaper approximation of gamma/sRGB such as using a square root. | |
| Jan 27, 2018 at 16:40 | history | edited | Tim Kuipers | CC BY-SA 3.0 |
Fix gamma compression formula
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| S Jan 27, 2018 at 16:03 | history | edited | Tim Kuipers | CC BY-SA 3.0 |
corrected a formatting error
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| S Jan 27, 2018 at 16:03 | history | suggested | Tare | CC BY-SA 3.0 |
corrected a formatting error
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| Jan 27, 2018 at 16:01 | comment | added | Tim Kuipers | The monitor calibration image is indeed kind of misleading for my argument. It does show that I should perform gamma expansion, but not which one. Am I correct to conclude that most images will likely be encoded with sRGB and I should use the formula provided by @Wyck? ($1.055L^{1/2.4}-0.055$) | |
| Jan 26, 2018 at 20:32 | comment | added | Wyck | A typical display is calibrated to sRGB, not gamma 2.2. So you should use the linear to sRGB or sRGB to linear conversions. And a 50% sRGB value should be 188, not 186. (see Wikipedia article for sRGB which says that a normalized 50% intensity should get an sRGB value of (1.055*0.5^(1/2.4))-0.055 = 0.735358, which is about 187.516 in 8-bit sRGB, hence the logic of encoding it as 188. | |
| Jan 26, 2018 at 14:52 | review | Suggested edits | |||
| S Jan 27, 2018 at 16:03 | |||||
| Jan 26, 2018 at 14:50 | comment | added | Dan Hulme | "The RGB values are most likely gamma compressed." That's common for 8-bit images, but you need to actually know, not just guess. Monitor calibration is a bit of a red herring nowadays, because applications should be drawing sRGB and the monitor should be interpreting its input as sRGB anyway. | |
| Jan 26, 2018 at 14:35 | review | First posts | |||
| Jan 30, 2018 at 9:11 | |||||
| Jan 26, 2018 at 14:32 | history | answered | Tim Kuipers | CC BY-SA 3.0 |