image processing - exposure effect on image

Question

I am currently working on an image processing android app. I am desperately looking for an exposure color matrix that I can use in order to change the exposure of an image. However, I could not find any usable code for that ;/

Is there anyone you could help me out please. I'd really appreciate it !

Don't you want to change the "brightness" (i.e. black to white), rather than the color compoents? — ErstwhileIII, Mar 15 '14 at 18:03
No I want the exposure color matrix, i already have a working brightness one :) — Andi, Mar 15 '14 at 21:03
It will be great to have it as a plugin to https://github.com/oliver-moran/jimp library. — mirik, Dec 23 '19 at 15:14

score 1 · Answer 1 · answered Apr 30 '14 at 17:51

1

Brightness: (Adjust all pixels by adding or subtracting a set amount)

[
   1, 0, 0, 0, v, //R
   0, 1, 0, 0, v, //G
   0, 0, 1, 0, v, //B
   0, 0, 0, 1, 0, //A
]

Exposure: (Adjust all pixels by using a consistent multiplier)

[
   v, 0, 0, 0, 0, //R
   0, v, 0, 0, 0, //G
   0, 0, v, 0, 0, //B
   0, 0, 0, 1, 0, //A
]

answered Apr 30 '14 at 17:51

Matt MacLean

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I think The second matrix is for contrast not for exposure – Raluca Lucaci May 26 '15 at 09:06

image processing - exposure effect on image

1 Answers1