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POCordova iOS - CANVAS get pixel color does not work properly (RETINA size)
 

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  1. POCordova iOS - CANVAS get pixel color does not work properly (RETINA size)
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    <p>In my application the user loads a photo from the library, displays it, and on a tap it gets the tapped pixel's color.</p> <p><em>I am using a variation of this snippet (first answer) <a href="https://stackoverflow.com/questions/6735470/get-pixel-color-from-canvas-on-mouseover">Get pixel color from canvas, on mouseover</a> to get the pixels color.</em></p> <p><strong>This does work if I use non-retina sizes</strong>:</p> <pre><code>var canvas = document.getElementById("myCanvas"); canvas.width = 300; canvas.height = 480; canvas.style.width = "300px"; canvas.style.height = "480px"; canvas.drawImage(img, 0, 0); </code></pre> <p>camera API:</p> <pre><code>navigator.camera.getPicture(funcSuccess, funcError, { quality: 100, targetWidth: 300, targetHeight: 480, destinationType: destinationType.FILE_URI, sourceType: source }); </code></pre> <h2>but as soon as I double the size for retina it will always returns a wrong color. (like it expects the image to be 600x960 instead of 300x480 displayed in a 600x960 canvas, ...I don't know)</h2> <pre><code>var canvas = document.getElementById("myCanvas"); canvas.width = 600; canvas.height = 960; canvas.style.width = "300px"; canvas.style.height = "480px"; canvas.drawImage(img, 0, 0); </code></pre> <p>camera API:</p> <pre><code>navigator.camera.getPicture(funcSuccess, funcError, { quality: 100, targetWidth: 600, targetHeight: 960, destinationType: destinationType.FILE_URI, sourceType: source }); </code></pre> <p>I appreciate every response. Thank you.</p>
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