# wx.canvasGetImageData(Object object, Object this)

Start from base library version 1.9.0. Please remaining backward compatible.

with Promise style call: Supported

Mini Program plugin: Support, need to Mini Program base library version no less than 1.9.6

Obtain canvas The pixel data implied by the region.

# parameter

# Object object

attribute	type	Required	Introductions
canvasId	string	yes	Canvas identity, passed in canvas Component `canvas-id` Property.
x	number	yes	The upper-left abscissa of the rectangular region of the image data to be extracted
and	number	yes	The upper-left ordinate of the rectangular region of image data to be extracted
width	number	yes	Width of rectangular region of image data to be extracted
height	number	yes	The height of the rectangular area of image data to be extracted
success	function	no	Interface calls the successful callback function
fail	function	no	Interface calls failed callback functions
complete	function	no	Interface calls the end of the callback function (call success or failure will be executed)

# object.success callback

# parameter

# Object res

attribute	type	Introductions
width	number	Width of image data rectangle
height	number	Height of image data rectangle
data	Uint8ClampedArray	Image pixel data, one-dimensional array, every four items representing a pixel rgba

# Object this

Under a custom component, the this of the current component instance to manipulate within the component canvas assembly

# sample code

Preview with Developer Tool

wx.canvasGetImageData({
  canvasId: 'myCanvas',
  x: 0,
  and: 0,
  width: 100,
  height: 100,
  success(res) {
    console.log(res.width) // 100
    console.log(res.height) // 100
    console.log(res.data instanceof Uint8ClampedArray) // true
    console.log(res.data.length) // 100 * 100 * 4
  }
})