Javascript 无法使用画布更改图像像素
我有这段代码,我想将灰色像素更改为all while,但它只是复制了testImage:Javascript 无法使用画布更改图像像素,javascript,canvas,Javascript,Canvas,我有这段代码,我想将灰色像素更改为all while,但它只是复制了testImage: $("body").append('<canvas id="canvas"></canvas>'); var image = document.getElementById('testImage'); var canvas = document.getElementById('canvas');
$("body").append('<canvas id="canvas"></canvas>');
var image = document.getElementById('testImage');
var canvas = document.getElementById('canvas');
canvas.width = image.width;
canvas.height = image.height;
var ctx = canvas.getContext("2d");
ctx.drawImage(image, 0, 0);
var imgData = ctx.getImageData(0, 0, canvas.width, canvas.height);
var data = imgData.data;
for (var i = 0; i < data.length; i += 4)
{
data[i] = data[i + 1] = data[i + 2] = data[i + 3] = 255;
}
ctx.putImageData(imgData, image.width, image.height);
$(“正文”)。附加(“”);
var image=document.getElementById('testImage');
var canvas=document.getElementById('canvas');
canvas.width=image.width;
canvas.height=image.height;
var ctx=canvas.getContext(“2d”);
ctx.drawImage(图像,0,0);
var imgData=ctx.getImageData(0,0,canvas.width,canvas.height);
var数据=imgData.data;
对于(变量i=0;i
我犯了什么错误?我想ctx.putImageData(imgData,0,0)是正确的我想ctx.putImageData(imgData,0,0)是正确的