我通过简单的前向映射而不是反向映射解决了这个问题,虽然反向映射通常更好,但在我的应用中,我只将矩形映射到比矩形小的四边形,所以变换后的图像通常没有空洞。 代码如下:
def reverse_quad_transform(image, quad_to_map_to, alpha):
# forward mapping, for simplicity
result = Image.new("RGBA",image.size)
result_pixels = result.load()
width, height = result.size
for y in range(height):
for x in range(width):
result_pixels[x,y] = (0,0,0,0)
p1 = (quad_to_map_to[0],quad_to_map_to[1])
p2 = (quad_to_map_to[2],quad_to_map_to[3])
p3 = (quad_to_map_to[4],quad_to_map_to[5])
p4 = (quad_to_map_to[6],quad_to_map_to[7])
p1_p2_vec = (p2[0] - p1[0],p2[1] - p1[1])
p4_p3_vec = (p3[0] - p4[0],p3[1] - p4[1])
for y in range(height):
for x in range(width):
pixel = image.getpixel((x,y))
y_percentage = y / float(height)
x_percentage = x / float(width)
# interpolate vertically
pa = (p1[0] + p1_p2_vec[0] * y_percentage, p1[1] + p1_p2_vec[1] * y_percentage)
pb = (p4[0] + p4_p3_vec[0] * y_percentage, p4[1] + p4_p3_vec[1] * y_percentage)
pa_to_pb_vec = (pb[0] - pa[0],pb[1] - pa[1])
# interpolate horizontally
p = (pa[0] + pa_to_pb_vec[0] * x_percentage, pa[1] + pa_to_pb_vec[1] * x_percentage)
try:
result_pixels[p[0],p[1]] = (pixel[0],pixel[1],pixel[2],min(int(alpha * 255),pixel[3]))
except Exception:
pass
return result
im.transform(size, PERSPECTIVE, data) image
正在做你想要实现的功能。 - physicalattraction