Another minor optimization
Initialize tempDistance to a huge number (greater than the distance from
ff000 to0000ff) and then simplify the if
Ron
Darren Cook wrote:
Hi,
A minor optimization, but you can drop the Math.sqrt(). I.e.
x^2 > y^2 == x > y
for all positive values of x and y.
Darren
That's what I actually ended up doing, and it worked out pretty good:
private function getClosest (red1:Number, green1:Number,
blue1:Number):Number {
var totalColors:Number = __palette.length;
var tempDistance:Number;
var closestColor:Number;
for (var i:Number = 0; i < totalColors; i++) {
// first, break up the color to check
var red2:Number = (__palette[i] & 0xFF0000) >>> 16;
var green2:Number = (__palette[i] & 0x00FF00) >>> 8;
var blue2:Number = __palette[i] & 0x0000FF;
// now, get the distance from the source
var tempD:Number = Math.sqrt ((Math.abs(red1 - red2) ^ 2) +
(Math.abs(green1 - green2) ^ 2) + (Math.abs(blue1 - blue2) ^ 2));
if ((tempD <= tempDistance) || tempDistance == undefined) {
tempDistance = tempD;
closestColor = __palette[i];
}
}
return closestColor;
}
- Josh
On Mar 16, 2006, at 7:59 PM, Ron Wheeler wrote:
If a color can be treated as a point in a 3-d cube 256 units on each
side, you can use the formula in this reference
http://www.uwm.edu/~ericskey/TANOTES/Ageometry/node10.html
to calculate the "distance" between 2 colors.
I have not tried this but it would seem logical that this would work
Ron
elibol wrote:
K, here is some better math for getRGB, performance will probably be
important:
return [c>>>16, c>>8&~0xFF00, c&~0xFFFFF00];
You can also try using the ColorTransform or Color class to get the rgb
values, except they might be slower than getting the raw math right.
M.
On 3/15/06, Josh Buhler <[EMAIL PROTECTED]> wrote:
Thanks - I'll give it a shot and see how it goes.
- Josh
On Mar 15, 2006, at 3:10 PM, elibol wrote:
I tried comparing the hex values directly, but there were
inaccuracies,
maybe the same ones you've been having. I think since the value of a
particular color precedes with a 0 even when it's below 17(0F), the
preceding 0 causes a shifting in the comparison. It would, for
example,
cause 0x000000 to seem farther to 0x123456 than 0x00FF00, where
visually you
can see clearly that black is closer to 0x000000.
btw in my example, var a = 0x12345 where it should be 0x123456.
The numbers hold to be accurate after correcting this typo.
On 3/15/06, Josh Buhler <[EMAIL PROTECTED]> wrote:
I'm working on a project that requires that I take an uploaded
image,
and convert it to use a limited palette of colors - around 5-10
colors.
I've got the custom palette I have to work with stored in an array,
and for each color in my image, I've got it finding the color in the
array it's closest to numerically, but the results aren't exactly
what I'm looking for.
Does anybody know of any formulas available for comparing multiple
colors and finding the ones that are the closest matches? I've been
searching Google for a while, with no luck. Any good resources on
color formulas & such would be appreciated.
- Josh
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
_______________________________________________
[email protected]
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
