javascript - 未捕获错误 : INDEX_SIZE_ERR: DOM Exception 1, getImageData

Question

我正在使用以下代码将图像转换为灰度，在本地计算机上它很好，但是当我在服务器上部署相同的代码时，它会传递未捕获错误:INDEX_SIZE_ERR:DOM异常1我想知道是由于域不同，我不确定，但问题是由于“getImageData”引起的。另外，此问题仅在 chrome 上出现。

我读了很多帖子并尝试了很多，但似乎没有什么对我有用。

提前致谢...

function grayscale(img) {
         var canvas = document.createElement('canvas');
         var ctx = canvas.getContext('2d');
         var imgObj = new Image();
         imgObj.src = img;
         canvas.width = imgObj.width;
         canvas.height = imgObj.height;
         ctx.drawImage(imgObj, 0, 0);
         var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);
         for (var y = 0; y < imgPixels.height; y++) {
         for (var x = 0; x < imgPixels.width; x++) {
         var i = (y * 4) * imgPixels.width + x * 4;
         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;
                }
            }
            ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
            return canvas.toDataURL();
        }

Answer 1

这对我来说效果很好

// img is HTMLImageElement
function makeGreyScale(img) {
  var canvas = document.createElement('canvas');
  var ctx = canvas.getContext('2d');
  var imgObj = new Image();
  imgObj.src = img.src;
  imgObj.onload = function(){
    canvas.width = imgObj.width;
    canvas.height = imgObj.height;
    ctx.drawImage(imgObj, 0, 0);
    var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);

    for(var y = 0; y < imgPixels.height; y++){
      for(var x = 0; x < imgPixels.width; x++){
        var i = (y * 4) * imgPixels.width + x * 4;
        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;
      }
    }
    ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
    img.src= canvas.toDataURL();
  };
}