Question

所以我对这个Python事物真的很陌生，我正在使用JES并试图弄清楚如何裁剪图像。我一直收到“show（croppedPicture）”无效的错误，我可以使用我现在可以获得的任何帮助。到目前为止，这是我的代码：

def main():
print "Select the Media Folder"
  setMediaFolder()
  print "Select the picture (.jpg) file to crop"
  fileName = pickAFile()
  pict = makePicture(fileName)
  show(pict)

  startX = requestIntegerInRange("Enter X coordinate of upper, left-hand corner",0,getWidth(pict)-1)
  startY = requestIntegerInRange("Enter Y coordinate of upper, left-hand corner",0,getHeight(pict)-1)

  endX = requestIntegerInRange("Enter X coordinate of lower, right-hand corner",startX,getWidth(pict)-1)
  endY = requestIntegerInRange("Enter Y coordinate of lower, right-hand corner",startY,getHeight(pict)-1)      



  print "Please wait while picture is cropped from (",startX,",",startY,") to (",endX,",",endY,")."
  croppedPicture = makeCroppedPicture(pict, startX, startY, endX, endY)
  show(croppedPicture)

  newFileName = getMediaPath('croppedPicture.jpg')
  writePictureTo(croppedPicture, newFileName)

def makeCroppedPicture(pict, startX, startY, endX, endY):
  """ Makes and returns a cropped rectangular region of a picture into a new picture """

  target = makeEmptyPicture

def crop(picture):
  def crop(picture):
  width = getWidth(pict)
  height = getHeight(pict)
  canvas = makeEmptyPicture(width, height)
  targetX = 100
  for sourceX in range(100,30):
    targetY = 100
    for sourceY in range(311,433):
      color = getColor(getPixel(pict, sourceX, sourceY))
      setColor(getPixel(canvas, targetX, targetY),color)
      targetY = targetY + 1
    targetX = targetX + 1
  show(pict)
  return canvas  

  return target   # returns the cropped picture

main() # starts the program

Answer 1

粘贴代码似乎有些不对劲;第2行缺少它的缩进，并且在第3行有一个虚假的“在这里添加代码”字符串（在crop（）函数的定义周围出现了一些奇怪的错误，因为在代码运行之前需要纠正缩进！）。

也就是说，通过删除当前未使用的第29-43行删除crop（）函数，然后问题变得更加容易看到...

   def makeCroppedPicture(pict, startX, startY, endX, endY):
       target = makeEmptyPicture
       return target   # returns the cropped picture

行target = makeEmptyPicture发生的是你将变量target分配给实际的函数makeEmptyPicture，而不是通过调用该函数返回的内容。

有兴趣的话，关于你如何/为什么要在帖子Assigning a function to a variable中真正想要这样做的更多内容。

要解决这个问题，只需在调用makeEmptyPicture时为裁剪后的图像的高度和宽度添加两个参数。注：你可以硬编码几个数字来检查它是否正常工作。即target = makeEmptyPicture(50, 50)

在JES中剪切图像（Python）

1 个答案: