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Optimized JPG.js - 33% faster convertCmykToRgb

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p01 2014-04-30 15:54:31 +02:00
parent 287274d3dc
commit 14a2d74d16
1 changed files with 29 additions and 28 deletions
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57
src/core/jpg.js
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@ -943,50 +943,51 @@ var JpegImage = (function jpegImage() {
_convertCmykToRgb: function convertCmykToRgb(data) {
var c, m, y, k;
var offset = 0;
for (var i = 0; i < data.length; i += this.numComponents) {
c = data[i ] * 0.00392156862745098;
m = data[i + 1] * 0.00392156862745098;
y = data[i + 2] * 0.00392156862745098;
k = data[i + 3] * 0.00392156862745098;
var length = data.length;
var min = -255 * 255 * 255;
var scale = 1 / 255 / 255;
for (var i = 0; i < length;) {
c = data[i++];
m = data[i++];
y = data[i++];
k = data[i++];
var r =
c * (-4.387332384609988 * c + 54.48615194189176 * m +
18.82290502165302 * y + 212.25662451639585 * k +
-285.2331026137004) +
m * (1.7149763477362134 * m - 5.6096736904047315 * y +
-17.873870861415444 * k - 5.497006427196366) +
18.82290502165302 * y + 212.25662451639585 * k -
72734.4411664936) +
m * (1.7149763477362134 * m - 5.6096736904047315 * y -
17.873870861415444 * k - 1401.7366389350734) +
y * (-2.5217340131683033 * y - 21.248923337353073 * k +
17.5119270841813) +
k * (-21.86122147463605 * k - 189.48180835922747) + 255;
4465.541406466231) -
k * (21.86122147463605 * k + 48317.86113160301);
var g =
c * (8.841041422036149 * c + 60.118027045597366 * m +
6.871425592049007 * y + 31.159100130055922 * k +
-79.2970844816548) +
6.871425592049007 * y + 31.159100130055922 * k -
20220.756542821975) +
m * (-15.310361306967817 * m + 17.575251261109482 * y +
131.35250912493976 * k - 190.9453302588951) +
y * (4.444339102852739 * y + 9.8632861493405 * k - 24.8674158255588) +
k * (-20.737325471181034 * k - 187.80453709719578) + 255;
131.35250912493976 * k - 48691.05921601825) +
y * (4.444339102852739 * y + 9.8632861493405 * k -
6341.191035517494) -
k * (20.737325471181034 * k + 47890.15695978492);
var b =
c * (0.8842522430003296 * c + 8.078677503112928 * m +
30.89978309703729 * y - 0.23883238689178934 * k +
-14.183576799673286) +
30.89978309703729 * y - 0.23883238689178934 * k -
3616.812083916688) +
m * (10.49593273432072 * m + 63.02378494754052 * y +
50.606957656360734 * k - 112.23884253719248) +
y * (0.03296041114873217 * y + 115.60384449646641 * k +
-193.58209356861505) +
k * (-22.33816807309886 * k - 180.12613974708367) + 255;
50.606957656360734 * k - 28620.90484698408) +
y * (0.03296041114873217 * y + 115.60384449646641 * k -
49363.43385999684) -
k * (22.33816807309886 * k + 45932.16563550634);
data[offset++] = clamp0to255(r);
data[offset++] = clamp0to255(g);
data[offset++] = clamp0to255(b);
data[offset++] = r >= 0 ? 255 : r <= min ? 0 : 255 + r * scale | 0;
data[offset++] = g >= 0 ? 255 : g <= min ? 0 : 255 + g * scale | 0;
data[offset++] = b >= 0 ? 255 : b <= min ? 0 : 255 + b * scale | 0;
}
return data;
},
getData: function getData(width, height, forceRGBoutput) {
var i;
var Y, Cb, Cr, K, C, M, Ye, R, G, B;
var colorTransform;
if (this.numComponents > 4) {
throw 'Unsupported color mode';
}