在Python (JES)中水平翻转图像

Question

我需要做一个函数，将复制一个图像，但镜像。我创建了镜像的代码，但它不工作，我不知道为什么，因为我跟踪了代码，它应该镜像镜像。代码如下：

def invert(picture):
 width = getWidth(picture)
 height = getHeight(picture)

 for y in range(0, height):
   for x in range(0, width):
    sourcePixel = getPixel(picture, x, y)
    targetPixel = getPixel(picture, width - x - 1, height - y - 1)
    color = getColor(sourcePixel)
    setColor(sourcePixel, getColor(targetPixel))
    setColor(targetPixel, color)
 show(picture)
 return picture 

def main():
  file = pickAFile()
  picture = makePicture(file)
  newPicture = invert(picture)
  show(newPicture)

有人能给我解释一下出了什么问题吗？谢谢。

Answer 1

试试这个：

def flip_vert(picture):
    width = getWidth(picture)
    height = getHeight(picture)

    for y in range(0, height/2):
        for x in range(0, width):
            sourcePixel = getPixel(picture, x, y)
            targetPixel = getPixel(picture, x, height - y - 1)
            color = getColor(sourcePixel)
            setColor(sourcePixel, getColor(targetPixel))
            setColor(targetPixel, color)

    return picture 


def flip_horiz(picture):
    width = getWidth(picture)
    height = getHeight(picture)

    for y in range(0, height):
        for x in range(0, width/2):
            sourcePixel = getPixel(picture, x, y)
            targetPixel = getPixel(picture, width - x - 1, y)
            color = getColor(sourcePixel)
            setColor(sourcePixel, getColor(targetPixel))
            setColor(targetPixel, color)

    return picture 

Answer 2

问题是你是在整个图像上循环，而不是只有一半的宽度。你镜像你的图像两次，并得到与你输入的图像相同的输出图像。

如果你在Y轴上镜像，代码应该是

for y in range(0, height):
for x in range(0, int(width / 2)):