我知道這樣的問題已經有好幾次問了,但我還沒有找到我正在尋找的東西。我正在讀取一個圖像到一個畫布對象(在JavaScript中),並試圖操縱一些特定的像素。例如,我正在尋找顏色RGB:224 64 102,並試圖將其更改爲不同的顏色。Javascript像素操作:這些不是我的顏色
我可以將灰度應用於圖像,所以我知道操作有效,但代碼沒有找到具有此顏色的任何像素(即Adobe Illustrator所說的RGB顏色)。我希望我只是錯過了一個小細節。代碼如下,希望有人會看到它。
謝謝!
var canvas = document.getElementById("testcanvas");
var canvasContext = canvas.getContext('2d');
imgObj = new Image();
imgObj.src = "ss.jpg";
//imgObj.width = 200;
//imgObj.height = 200;
var imgW = imgObj.width;
var imgH = imgObj.height;
canvas.width = imgW;
canvas.height = imgH;
canvasContext.drawImage(imgObj, 0, 0);
var imgPixels = canvasContext.getImageData(0, 0, imgW, imgH);
//hash_table = {};
for (var x = 0; x < imgPixels.width; x++) {
for (var y = 0; y < imgPixels.height; y++)
{
var i = (y * imgPixels.width + x) * 4;
//Want to go from:
//E04066
//224 64 102 -> to
//134 135 185
if(imgPixels.data[i] == 224 && imgPixels.data[i+1] == 64 && imgPixels.data[i+2] == 102) {
imgPixels.data[i] = 134;
imgPixels.data[i+1] = 135;
imgPixels.data[i+2] = 185;
}
//To greyscale:
/*
var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2])/3;
imgPixels.data[i] = avg;
imgPixels.data[i + 1] = avg;
imgPixels.data[i + 2] = avg;
imgPixels.data[i + 3] = 255;
*/
}
}
canvasContext.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
//color_count = 0;
//for(key in hash_table) {
// color_count++;
//}
//console.log(color_count);
//console.log(hash_table);
return canvas.toDataURL();
});
});
</script>
</head>
<body>
<canvas id="testcanvas"></canvas>
<img src="ss.jpg" id="testimage"/>
您是否嘗試過使用all-(224 64 102)-image? – zambotn 2012-02-11 00:33:27