Question

假设我的最大图片尺寸为

totalpixels = (45, 45)

我想通过

拆分此图片

split_image = (10,20) #split the 45x45 pixels into 10x20 pixels

我可以得到的坐标列表是当我将45x45图像分割成10x20时

[(0,0), (10,0), (20,0), (30,0), (0,20), (10,20), (20,20), (30,20)]

因此，我从（0,0）坐标开始，从这里我添加

(0,0)
(10,0)    = (10,0)
(10+10,0) = (20,0)
(20+10,0) = (30,0)
(0,0+20)  = (0,20)    
(0+10,20) = (10,20)
(10+10,20)= (20,20)
(20+10,20)= (30,20)

我假设我必须制作两个for循环，

for x in range(total[0]): #Is the range supposed to be this?
    for y in range(total[1]):
         #I'm not sure how to append values according to the split value

Answer 1

for循环不是必需的：

>>> [(x, y) for x in range(0, 31, 10) for y in range(0, 21, 20)]
[(0, 0), (0, 20), (10, 0), (10, 20), (20, 0), (20, 20), (30, 0), (30, 20)]

此列表推导会生成您指定的结果。

范围的参数是start，stop和step。您为x指定了10的步长值，为y指定了20的步长值。请注意range在“停止”值（第二个参数）之前停止。因此，如果您希望最高“x”值为30，则需要使“停止”大于此值。

您似乎想要所有大小为split_image的像素块的边缘坐标，从（0,0）开始，适合但不超出，大小的图像totalpixels。计算它的一般函数是：

def coords(split_image, totalpixels): xstop = totalpixels[0] - split_image[0] ystop = totalpixels[1] - split_image[1] return [(x, y) for x in range(0, xstop, split_image[0]) for y in range(0, ystop, split_image[1])]

在参数值上运行时，它会产生：

>>> coords( (10, 20), (45, 45) ) [(0, 0), (0, 20), (10, 0), (10, 20), (20, 0), (20, 20), (30, 0), (30, 20)]

Answer 2

我认为你想使用带有步骤参数的范围：

range(start, stop[, step])

所以你可以这样做：

>>> result = []
>>> totalpixels = (45, 45) 
>>> split_image = (10,20) #split the 45x45 pixels into 10x20 pixels
>>> for x in range(0, totalpixels[0], split_image[0]):
...     for y in range(0, totalpixels[1], split_image[1]):
...             result.append((x,y))
... 
>>> result
[(0, 0), (0, 20), (0, 40), (10, 0), (10, 20), (10, 40), (20, 0), (20, 20), (20, 40), (30, 0), (30, 20), (30, 40), (40, 0), (40, 20), (40, 40)]
>>>

或者只是

>>> [(x, y) for x in range(0, totalpixels[0], split_image[0]) for y in range(0, totalpixels[1], split_image[1])]
[(0, 0), (0, 20), (0, 40), (10, 0), (10, 20), (10, 40), (20, 0), (20, 20), (20, 40), (30, 0), (30, 20), (30, 40), (40, 0), (40, 20), (40, 40)]

这会产生分割图像的坐标，如下所示：

   0    10     20   30     40 45
   +-----+-----+-----+-----+--+
   |     |     |     |     |  |
   |     |     |     |     |  |
20 +-----+-----+-----+-----+--+
   |     |     |     |     |  |
   |     |     |     |     |  |
40 +-----+-----+-----+-----+--+
   |     |     |     |     |  |
45 +-----+-----+-----+-----+--+

希望我能提供帮助。

创建坐标列表

2 个答案: