ImageData:mapPixel
Transform an image by applying a function to every pixel.
This function is a higher order function. It takes another function as a parameter, and calls it once for each pixel in the ImageData.
The function parameter is called with six parameters for each pixel in turn. The parameters are numbers that represent the x and y coordinates of the pixel and its red, green, blue and alpha values. The function parameter can return up to four number values, which become the new r, g, b and a values of the pixel. If the function returns fewer values, the remaining components are set to 0.
Function
Synopsis
function pixelFunction(x, y, r, g, b, a)
-- template for defining your own pixel mapping function
-- perform computations giving the new values for r, g, b and a
-- ...
return r, g, b, a
end
ImageData:mapPixel( pixelFunction )
Arguments
function pixelFunction- Function parameter to apply to every pixel.
Returns
Nothing.
