Re: Deciding whether text should be black or white for a given background color
Re: Deciding whether text should be black or white for a given background color
- Subject: Re: Deciding whether text should be black or white for a given background color
- From: Ricky Sharp <email@hidden>
- Date: Mon, 04 Dec 2006 13:10:45 -0800
On Monday, December 04, 2006, at 01:06PM, "Gregory Weston" <email@hidden> wrote:
>On Dec 4, 2006, at 1:57 PM, Keith Blount wrote:
>
>> The problem is, how do I programmatically decide what is a light-
>> and what is a dark-coloured background using methods available to
>> NSColor? Is there a well-known algorithm for deciding this?
>
>You might try the math used in this sample code as a starting point.
>
><http://developer.apple.com/samplecode/Monochrome_Image/index.html>
>
>The most interesting line for you, I'd think, is from
>NSImage_monochrome.m
>
>thisPixel->grayValue = rint(255 *
> (0.299 * [pixelColor redComponent]
> + 0.587 * [pixelColor greenComponent]
> + 0.114 * [pixelColor blueComponent]));
This is the NTSC weighted algorithm. I know it works very well (use it in my own app for grayscale conversions). Not sure how it will stack up for the original poster's problem, but it's definitely worth a shot to compare such results with the standard brightness computation.
--
Rick Sharp
Instant Interactive(tm)
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