圆柱投影python代码

下面是圆柱投影的Python实现代码：

from skimage.io import imread, imshow, imsave
from skimage.transform import resize
import math
import numpy as np

img = imread('img.jpg')
img = (resize(img, [1000, 800]) * 255).astype(np.uint8)

###圆柱投影
def cylindrical_projection(img, f):
    rows = img.shape[0]
    cols = img.shape[1]
    # f = cols / (2 * math.tan(np.pi / 8))
    blank = np.zeros_like(img)
    center_x = int(cols / 2)
    center_y = int(rows / 2)
    for y in range(rows):
        for x in range(cols):
            theta = math.atan((x - center_x) / f)
            point_x = int(f * math.tan((x - center_x) / f) + center_x)
            point_y = int((y - center_y) / math.cos(theta) + center_y)
            if point_x >= cols or point_x < 0 or point_y >= rows or point_y < 0:
                pass
            else:
                blank[y, x, :] = img[point_y, point_x, :]
    return blank

waved_img = cylindrical_projection(img, 500)
imshow(waved_img)

其中，`img`是原始图像，`f`是圆柱投影的参数，`waved_img`是圆柱投影后的图像。