CODEWITHSUNDEEP
javascriptcanvashtml5-canvas
Connor O'Hara
Connor O'Hara

Reputation: 139

Return pixels of a canvas object?

Is there a function in javascript to return an array of pixels taken up by an image object in canvas? Is there anyway to return a list of pixels taken up by an image object in canvas?

Upvotes: 1

Views: 278

Answers (2)

Leonard
Leonard

Reputation: 3092

Well, if you know the image object's position, it's possible to use the CanvasPixelArray:

https://developer.mozilla.org/En/HTML/Canvas/Pixel_manipulation_with_canvas

Upvotes: 0

Pointy
Pointy

Reputation: 413976

You can call ".getImageData()" on the context to get pixel values. You tell it the coordinates within the canvas to grab pixels from, and it gives you back an object with height, width, and pixels. The pixels are an array of integers, such that each pixel takes up 4 (red, green, blue, alpha). Thus there are height * width * 4 pixels in the array.

Here is the MDC page on the topic.

Upvotes: 2

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