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灰度图像

灰度图像

作者: 洛洛kkkkkk | 来源:发表于2017-04-20 19:26 被阅读0次
<!DOCTYPE html>
<html>

    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            #myCanvas {
                border: 10px solid red;
            }
        </style>
    </head>

    <body>
        <canvas id="myCanvas" width="600" height="600"></canvas>
    </body>
    <script type="text/javascript">
        var myCanvas = document.getElementById("myCanvas");
        var context = myCanvas.getContext("2d");

        var imgObj = new Image();
        imgObj.src = "AKL.jpg";

        imgObj.onload = function() {
            context.drawImage(imgObj, 0, 0);
            var imgData = context.getImageData(0,0,myCanvas.width,myCanvas.height);
            
            var pixels = imgData.data;
            //获取每个像素点的rgb
            for(var i=0;i<pixels.length;i+=4){
                var r=pixels[i];
                var g=pixels[i+1];
                var b=pixels[i+2];
                //灰度
//              var gray = (r+g+b)/3;
//              pixels[i]=gray;
//              pixels[i+1]=gray;
//              pixels[i+2]=gray;

                //反色
                pixels[i]=255-r;
                pixels[i+1]=255-g;
                pixels[i+2]=255-b;
        }
        context.putImageData(imgData,100,100);

        }
    </script>

</html>

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      本文标题:灰度图像

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