It must be very useful of a function equivalent to 'Color Range' selection in Photoshop can be realized with Flash.
First, I thought about majoring the distance of the color of each pixel to the sample color using the Pythagorean theorem, but I abandoned it because the workload to doing it pixel by pixel must be too heavy.
Instead of that, I made it with Bitmap.threshold method. This may be rather rough way of doing it, but the result is satisfactory and fast.
package {
import flash.display.*;
import flash.events.*;
import flash.geom.*;
public class BmpColorRange extends Sprite {
var src:BitmapData;
var canvas:BitmapData;
public function BmpColorRange(s:BitmapData) {
src = s;
canvas = new BitmapData(s.width, s.height, true, 0x00000000);
addChild(new Bitmap(canvas));
}
public function select(col:uint):void {
var tmp:BitmapData = new BitmapData(src.width, src.height, true, col | 0xff000000);
var r:uint, g:uint, b:uint, rmin:uint, gmin:uint, bmin:uint, rmax:uint, gmax:uint, bmax:uint;
var min:uint, max:uint;
var range:uint = 30;
r = col >> 16 & 0xfff;
g = col >> 8 & 0xff;
b = col & 0xff;
rmax = Math.max(0, r - range);
gmax = Math.max(0, g - range);
bmax = Math.max(0, b - range);
rmin = Math.min(255, r + range);
gmin = Math.min(255, g + range);
bmin = Math.min(255, b + range);
min = rmin << 16 | gmin << 8 | bmin;
max = rmax << 16 | gmax << 8 | bmax;
tmp.draw(src);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), ">=", min, 0xff000000, 0x00ff0000, true);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), ">=", min, 0xff000000, 0x0000ff00, true);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), ">=", min, 0xff000000, 0x000000ff, true);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), "<=", max, 0xff000000, 0x00ff0000, true);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), "<=", max, 0xff000000, 0x0000ff00, true);
tmp.threshold(tmp, new Rectangle(0, 0, tmp.width, tmp.height), new Point(0,0), "<=", max, 0xff000000, 0x000000ff, true);
canvas.draw(tmp);
}
}
}
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