The Flying Meat Wiki: AcornMakeGrayscalePlugin

And here is an example which takes the current bitmap layer and converts it to grayscale using CoreImage. It also setups a keyboard shortcut, using Control-Command-G:

MakeGrayscale.py

import objc

ACScriptSuperMenuTitle = "Color"

ACScriptMenuTitle = "Make Grayscale (python)"

ACShortcutKey = 'g'

ACShortcutMask = "command control"

CIColor  = objc.lookUpClass('CIColor')

CIFilter = objc.lookUpClass('CIFilter')

def main(image):

    color = CIColor.colorWithRed_green_blue_(0.5, 0.5, 0.5)

    filter = CIFilter.filterWithName_('CIColorMonochrome')

    filter.setDefaults()

    filter.setValue_forKey_(image, 'inputImage')

    filter.setValue_forKey_(color, 'inputColor')

    filter.setValue_forKey_(1, 'inputIntensity')

    return filter.valueForKey_('outputImage')

Back to AcornPlugins

The Flying Meat Wiki : AcornMakeGrayscalePlugin