Jython：减少一半图像的颜色

Question

我试图减少下半部分图像中的红色，但我很困惑，这是我想出的代码，只是想知道是否有人可以指出为什么它对我不起作用？

def decreaseRed(pict):

width=getWidth(pict)
height=getHeight(pict)
canvas=makeEmptyPicture(width,height)
for x in range(0, width):
 for y in range(0, height/2):
  pixel = getPixel(pict,x,y)
  newRed = getRed(pixel)*0.5
  newGreen = getGreen(pixel)
  newBlue = getBlue(pixel)
  newColor = makeColor(newRed,newGreen,newBlue)
  pixelCanvas = getPixel(canvas,x,y)
  setColor(pixelCanvas,newColor)
  show(pict)
  show(canvas)

file=getMediaPath("testa.jpg")
pict=makePicture(file)

decreaseRed(pict)

Answer 1

我相信我找到了答案，这会将图像下半部分的红色减少到原始颜色的 70%。

def decreaseRed(pict):

  width=getWidth(pict)
  height=getHeight(pict)
  canvas=makeEmptyPicture(width,height)
  for x in range(0, width):
    for y in range(0, height):
      pixel = getPixel(pict,x,y)
      newRed = getRed(pixel)
      newGreen = getGreen(pixel)
      newBlue = getBlue(pixel)
      newColor = makeColor(newRed,newGreen,newBlue)
      pixelCanvas = getPixel(canvas,x,y)
      setColor(pixelCanvas,newColor)
    for y in range(height/2,height):
      pixel = getPixel(pict,x,y)
      newRed = getRed(pixel)*0.7
      newGreen = getGreen(pixel)
      newBlue = getBlue(pixel)
      newColor = makeColor(newRed,newGreen,newBlue)
      pixelCanvas = getPixel(canvas,x,y)
      setColor(pixelCanvas,newColor)
  return canvas
file=getMediaPath("test.jpg")
pict=makePicture(file)

show(decreaseRed(pict))

Jython：减少一半图像的颜色

Jython: reducing color in half an image

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