Get pixel color from an image

image, javascript, pixel

Solution

- Create a canvas document.createElement

- Get the 2d context `canvas.getContext('2d')`

- Draw the image to the canvas `context.drawImage(image, x, y)`

- Make sure the image is from the same domain or you won't have access to its pixels

- Get the pixel data for the image `context.getImageData(x1, y1, x2, y2)`

- You want just the top left so `context.getImageData(0, 0, 1, 1)`

- The result of getImageData will have an array of pixels in it's `data` field `(context.getImageData(0,0,1,1).data`)

- The array will have `r`, `g`, `b` and `a` values.

Problem

I have an image on a browser. I want to get the top left pixel of the image color (at coordinates: 0,0), no matter whether the image is rotated or not. How can I do that, using javascript or php code?

Original source

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