如何将PNG中特定RGB的所有像素替换为javascript中的另一个RGB？

// 创建一个Canvas元素
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');

// 绘制PNG图像到Canvas
var img = new Image();
img.onload = function() {
  canvas.width = img.width;
  canvas.height = img.height;
  ctx.drawImage(img, 0, 0);

  // 获取图像数据
  var imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
  var data = imageData.data;

  // 遍历像素数据
  for (var i = 0; i < data.length; i += 4) {
    var r = data[i];
    var g = data[i + 1];
    var b = data[i + 2];

    // 检查RGB值是否匹配特定RGB
    if (r === 255 && g === 0 && b === 0) {
      // 替换为目标RGB值
      data[i] = 0;
      data[i + 1] = 255;
      data[i + 2] = 0;
    }
  }

  // 将修改后的图像数据重新绘制到Canvas
  ctx.putImageData(imageData, 0, 0);

  // 将Canvas内容转换为DataURL并下载
  var downloadLink = document.createElement('a');
  downloadLink.href = canvas.toDataURL('image/png');
  downloadLink.download = 'modified_image.png';
  downloadLink.click();
};

// 加载PNG图像
img.src = 'path/to/image.png';