Created
May 30, 2016 08:54
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crates canvas with onclick event to get value of a clicked pixel
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| <html> | |
| <head> | |
| </head> | |
| <body> | |
| <img style="display:none" src="image.png" alt=""> | |
| <canvas id="canvas" onClick="selectPixel(this,event)"></canvas> | |
| <script> | |
| window.onload = function() { | |
| var myImg = document.querySelector("img"); | |
| var canvas = document.getElementById("canvas"); | |
| var context = canvas.getContext("2d"); | |
| context.drawImage(myImg, 0, 0); | |
| } | |
| var selectPixel = function ($this,event){ | |
| console.log(event.offsetX,event.offsetY); | |
| getImageData(event.offsetX,event.offsetY); | |
| } | |
| var getImageData = function (x,y) { | |
| var canvas = document.getElementById("canvas"); | |
| var context = canvas.getContext("2d"); | |
| data = context.getImageData(x, y, 1, 1); | |
| //returns rgba() | |
| console.log(data); | |
| } | |
| </script> | |
| </body> | |
| </html> |
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