我想将彩色图像更改为灰度,但是当我尝试使用getImageData时出现安全性错误.
Uncaught SecurityError: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The canvas has been tainted by cross-origin data.
我知道这个错误已经到处讨论过,但没有一个有明确的解决方案.请帮忙!
<html>
<script>
function grayscale()
{
var myCanvas = document.getElementById("c1");
var myCanvasContext = myCanvas.getContext("2d");
var img = document.getElementById("myImage");
img.crossOrigin = "anonymous";
var imgWidth = img.width;
var imgHeight = img.height;
myCanvas.width = imgWidth;
myCanvas.height = imgHeight;
myCanvasContext.drawImage(img,0,0);
var imageData = myCanvasContext.getImageData(0,0, imgWidth, imgHeight);
for (j=0; j<imageData.height; i++)
{
for (i=0; i<imageData.width; j++)
{
var index=(i*4)*imageData.width+(j*4);
var red=imageData.data[index];
var green=imageData.data[index+1];
var blue=imageData.data[index+2];
var alpha=imageData.data[index+3];
var …