合并两张图片，乘以RGB值以制作渐晕效果 Jython/Python

Question

https://i.stack.imgur.com/AAtUD.jpg https://i.stack.imgur.com/eouLY.jpg

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这是用来写代码的图片。

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我想要实现的最终效果是把一个渐晕的图片和一个CGI图片结合在一起。因为渐晕图片的边缘RGB值比较暗，所以我需要把原始图片中对应像素的值乘以边缘的较小值，这样就能让原始图片的边缘变得更暗，形成一个暗边框。

这是我目前写的代码：

  def addVignette(inputPic, vignette):
   #create empty canvas to combine images correctly
   canvas = makeEmptyPicture(getWidth(inputPic), getHeight(inputPic))

   for x in range(0, getWidth(inputPic)):
     for y in range(0, getHeight(inputPic)):
       px = getPixel(canvas, x, y)
       inputPx = getPixel(inputPic, x, y)
       vignettePx = getPixel(vignette, x, y)

      #make a new color from these values
       newColour = getNewColorValues(vignettePx,inputPx)

      #then assign this new color to the current pixel of the input image
       setColor(px, newColour)

  explore(canvas)

def getNewColourValues(inputPx, vignettePx):

   inputRed = getRed(inputPx)
   vignetteRed = getRed(vignettePx)
   inputGreen = getGreen(inputPx)
   vignetteGreen = getGreen(vignettePx)
   inputBlue = getBlue(inputPx)
   vignetteBlue = getBlue(vignettePx)


   newRGB= setColor(inputPx,inputRed,inputGreen,inputBlue)*(vignettePx,vignetteRed,vignetteGreen,vignetteBlue)


   newColour = makeColor(newRGB) 

   return newColour

def newPicture(newColour):

 folder = pickAFolder()
 filename = requestString("enter file name: ")
 path = folder+filename+".jpg"

 writePictureTo(inputPic, path) 

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在测试的时候，先用渐晕的图片，然后再用CGI图片。另外，保存图片的功能一直没能实现，尽管我一直在尝试，如果有人能帮忙就太好了。

Answer 1

你也可以试着在计算机视觉（CV）中这样做。单个像素的操作和文件输入输出（I/O）都比较简单。

img = cv2.imread('test.jpg')
pixel = img[10,10]

我在计算机视觉中从来没有遇到过文件输入输出的问题。可能是权限错误或者多余的空格导致的。

cv2.imwrite('messigray.png',img)

你还可以做一些简单的图像预览，这样可以让你更好地实验输出效果。

Answer 2

保存图片

首先，我们来聊聊怎么保存图片。从你发的代码来看，你其实没有调用 newPicture() 这个函数，所以图片就没有被保存。另外，我还注意到在 newPicture 函数里，你没有把新图片的引用传给这个函数。

下面是我的解决方案。我把函数的名字从 newPicture 改成了 saveNewImage()。

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添加渐变效果

请查看 getNewColorValues() 函数中用 ******* 标记的代码块的注释。

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你需要运行 Main() 函数才能让这个脚本工作

# Main function.
# *** THIS FUNCTION NEEDS TO BE CALLED IN THE CONSOLE ***
# i.e >>> main()

def main():

  # Choose the files you wish to use
  inputFile = pickAFile()
  vignetteFile = pickAFile()

  # Turn both files into picture objects
  inputPic = makePicture(inputFile)
  vignette = makePicture(vignetteFile)

  # addVignette() function combines the input picture and vignette together
  # and returns the result as a new picture object
  newImage =  addVignette(inputPic, vignette)

  # saveNewImage() function stores the new image as file
  saveNewImage(newImage)


# Main() calls this function to add input picture and vignette together  
def addVignette(inputPic, vignette):

  # Create empty canvas
  canvas = makeEmptyPicture(getWidth(inputPic), getHeight(inputPic))

  # Iterate through all the pixels of the input image. x and y are
  # used as the current coordinates of the pixel
  for x in range(0, getWidth(inputPic)):
    for y in range(0, getHeight(inputPic)):

      # Get the current pixels of inputPic and vignette
      inputPixel = getPixel(inputPic, x, y)
      vignettePixel = getPixel(vignette, x, y)

      # The getNewColorValues() function, makes a new color from those
      # values
      newColor = getNewColorValues(inputPixel, vignettePixel)

      # Assign this new color to the current pixel of the canvas
      px = getPixel(canvas, x, y)      
      setColor(px, newColor)

  # Show the result of combiming the input picture with the vignette
  explore(canvas)

  # return the new image to main() function.
  return canvas

# Called from the addVignette() function to add the color values from
# the input picture and vignette together. It returns a new color
# object
def getNewColorValues(inputPixel, vignettePixel):

  # Get the individual colour values
  inputRed = getRed(inputPixel)
  vignetteRed = getRed(vignettePixel)
  inputGreen = getGreen(inputPixel)
  vignetteGreen = getGreen(vignettePixel)
  inputBlue = getBlue(inputPixel)
  vignetteBlue = getBlue(vignettePixel)

  # ***********************************************************
  # Most important part. This will determine if the pixel is darkent
  # and by how much. How it works is the darker the vignette pixel the less that will
  # be taken away from 255. This means the result of `255 - vignetteRed` will be a higher
  # value which means more will be taken away from the input colour.
  # The light the vignette pixel the less that will be taken away from input pixel

  newR = inputRed - (255 - vignetteRed)
  newG = inputGreen - (255 - vignetteGreen)
  newB = inputBlue - (255 - vignetteBlue)
  # ***********************************************************

  newC = makeColor(newR, newG, newB)
  return newC

# Called from the main() function in order to save the new image  
def saveNewImage(newImage):

  folder = pickAFolder()
  filename = requestString("Please enter file name: ")
  path = folder + filename + ".jpg"

  writePictureTo(newImage, path)