How to scale an imageData in HTML canvas?

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礼貌的吻别
礼貌的吻别 2020-12-01 05:37

I have a canvas in my webpage; I create a new Image data in this canvas then I modify some pixel through myImgData.data[] array. Now I would like to scale this image and mak

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  •  暗喜
    暗喜 (楼主)
    2020-12-01 05:57

    You could draw the imageData to a new canvas, scale the original canvas and then draw the new canvas to the original canvas.

    Something like this should work:

    var imageData = context.getImageData(0, 0, 100, 100);
    var newCanvas = $("")
        .attr("width", imageData.width)
        .attr("height", imageData.height)[0];
    
    newCanvas.getContext("2d").putImageData(imageData, 0, 0);
    
    context.scale(1.5, 1.5);
    context.drawImage(newCanvas, 0, 0);
    

    Here's a functioning demo http://jsfiddle.net/Hm2xq/2/.

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