從HTML畫(huà)布中獲取Pixel是否可以查詢HTML畫(huà)布對(duì)象以獲得特定位置的顏色？
3 回答
墨色風(fēng)雨
TA貢獻(xiàn)1853條經(jīng)驗(yàn) 獲得超6個(gè)贊
// Get the CanvasPixelArray from the given coordinates and dimensions.var imgd = context.getImageData(x, y, width, height);
var pix = imgd.data;// Loop over each pixel and invert the color.for (var i = 0, n = pix.length; i < n; i += 4) {
pix[i ] = 255 - pix[i ]; // red
pix[i+1] = 255 - pix[i+1]; // green
pix[i+2] = 255 - pix[i+2]; // blue
// i+3 is alpha (the fourth element)}// Draw the ImageData at the given (x,y) coordinates.context.putImageData(imgd, x, y);
慕神8447489
TA貢獻(xiàn)1780條經(jīng)驗(yàn) 獲得超1個(gè)贊
var data = context.getImageData(x, y, 1, 1).data;var rgb = [ data[0], data[1], data[2] ];
郎朗坤
TA貢獻(xiàn)1921條經(jīng)驗(yàn) 獲得超9個(gè)贊
var imgData = context.getImageData(0,0,canvas.width,canvas.height);// { data: [r,g,b,a,r,g,b,a,r,g,..], ... }function getPixel(imgData, index) {
var i = index*4, d = imgData.data;
return [d[i],d[i+1],d[i+2],d[i+3]] // returns array [R,G,B,A]}// AND/ORfunction getPixelXY(imgData, x, y) {
return getPixel(imgData, y*imgData.width+x);}添加回答
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