Differences
This shows you the differences between two versions of the page.
| Next revisionBoth sides next revision |
isp:brightness [2019/05/08 16:37] – created Igor Yefmov | isp:brightness [2019/05/09 00:30] – Igor Yefmov |
---|
====== Brightness ====== | ====== Brightness ====== |
| |
In the simplest terms the "brightness" of a pixel is its luminosity value as perceived by a human eye (making infrared and gamma rays ''0'' "bright"). There are quite a few competing standards and definitions of what the means exactly, but for our purposes we will use the ''L'' component of the HSL color space as our "brightness" value of a pixel. | In the simplest terms the "brightness" of a pixel is its luminosity value as perceived by a human eye (making infrared and gamma rays \(0\) "bright"). There are quite a few competing standards and definitions of what the means exactly, but for our purposes we will use the \(L\) component of the HSL color space as our "brightness" value of a pixel. |
| |
Again, in the simplest terms, increasing or reducing pixel's brightness can be interpreted as adding or subtracting a fixed "gain" value (others may argue that a more natural approach would be to use a multiplier, while others still may bring the "vibrancy" approach into picture). | Again, in the simplest terms, increasing or reducing pixel's brightness can be interpreted as adding or subtracting a fixed "gain" value (others may argue that a more natural approach would be to use a multiplier, while others still may bring the "vibrancy" approach into picture). |
| |
With that the implementation of the Brightness adjustment can be as simple as the following (where the "luma", or brightness component is in range ''[0..100]''%): | With that the implementation of the Brightness adjustment can be as simple as the following (where the "luma", or brightness component \(\in[0..100]%%\)): |
<code c++>// pseudo-code | <code c++>// pseudo-code |
void brightness(/*array of pixels*/image, int _br){ | void brightness(/*array of pixels*/image, int _br){ |