我嘗試創建一個腳本,改變圖像的色彩,我找到了一種方法來改變顏色,但因爲圖像有一個白色的背景,改變了所有的形象,是可以忽略的白色像素不知何故?畫布中的白色像素是透明的嗎?
這是迄今爲止代碼:
<!doctype html>
<html>
<head>
</head>
<body>
<h4>Original Image</h4>
<img id="testImage" src='../src/test.png'/>
<h4>Image copied to canvas</h4>
<canvas id="canvas" width="500" height="500"></canvas>
<h4>Modified Image copied to an image tag</h4>
<img id="imageData"/>
<script>
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
image = document.getElementById("testImage");
ctx.drawImage(image,0,0);
var imgd = ctx.getImageData(0, 0, 128, 128),
pix = imgd.data,
uniqueColor = [0,0,150]; // Blue for an example, can change this value to be anything.
// Loops through all of the pixels and modifies the components.
for (var i = 0, n = pix.length; i <n; i += 4) {
pix[i] = uniqueColor[0]; // Red component
pix[i+1] = uniqueColor[1]; // Blue component
pix[i+2] = uniqueColor[2]; // Green component
//pix[i+3] is the transparency.
}
ctx.putImageData(imgd, 0, 0);
var savedImageData = document.getElementById("imageData");
savedImageData.src = canvas.toDataURL("image/png");
</script>
</body>
</html>
您將要使用@aglassman的答案。但是爲圖像製作一個畫布元素並在啓動時處理它。然後將畫布元素繪製到畫布上。這將顯着提高性能。 – 2012-03-06 18:59:27