我想使用 Python OpenCV 在圖像上應用收縮/凸出濾鏡。結果應該是這個例子的某種形式：https://pixijs.io/pixi-filters/tools/screenshots/dist/bulge-pinch.gif我讀過以下 stackoverflow 帖子，它應該是過濾器的正確公式：Formulas for Barrel/Pincushion Distortion但我正在努力在 Python OpenCV 中實現這一點。我讀過有關在圖像上應用濾鏡的地圖：使用 OpenCv-python 的扭曲效果根據我的理解，代碼可能如下所示：import numpy as npimport cv2 as cvf_img = 'example.jpg'im_cv = cv.imread(f_img)# grab the dimensions of the image(h, w, _) = im_cv.shape# set up the x and y maps as float32flex_x = np.zeros((h, w), np.float32)flex_y = np.zeros((h, w), np.float32)# create map with the barrel pincushion distortion formulafor y in range(h): for x in range(w): flex_x[y, x] = APPLY FORMULA TO X flex_y[y, x] = APPLY FORMULA TO Y# do the remap this is where the magic happensdst = cv.remap(im_cv, flex_x, flex_y, cv.INTER_LINEAR)cv.imshow('src', im_cv)cv.imshow('dst', dst)cv.waitKey(0)cv.destroyAllWindows()這是實現示例圖像中呈現的失真的正確方法嗎？非常感謝有關有用資源或最好的示例的任何幫助。
1 回答
搖曳的薔薇
TA貢獻1793條經驗 獲得超6個贊
在熟悉了 ImageMagick 源代碼后，我找到了一種應用失真公式的方法。借助OpenCV 重映射函數，這是一種扭曲圖像的方法：
import numpy as np
import cv2 as cv
f_img = 'example.jpg'
im_cv = cv.imread(f_img)
# grab the dimensions of the image
(h, w, _) = im_cv.shape
# set up the x and y maps as float32
flex_x = np.zeros((h, w), np.float32)
flex_y = np.zeros((h, w), np.float32)
# create map with the barrel pincushion distortion formula
for y in range(h):
? ? delta_y = scale_y * (y - center_y)
? ? for x in range(w):
? ? ? ? # determine if pixel is within an ellipse
? ? ? ? delta_x = scale_x * (x - center_x)
? ? ? ? distance = delta_x * delta_x + delta_y * delta_y
? ? ? ? if distance >= (radius * radius):
? ? ? ? ? ? flex_x[y, x] = x
? ? ? ? ? ? flex_y[y, x] = y
? ? ? ? else:
? ? ? ? ? ? factor = 1.0
? ? ? ? ? ? if distance > 0.0:
? ? ? ? ? ? ? ? factor = math.pow(math.sin(math.pi * math.sqrt(distance) / radius / 2), -amount)
? ? ? ? ? ? flex_x[y, x] = factor * delta_x / scale_x + center_x
? ? ? ? ? ? flex_y[y, x] = factor * delta_y / scale_y + center_y
# do the remap? this is where the magic happens
dst = cv.remap(im_cv, flex_x, flex_y, cv.INTER_LINEAR)
cv.imshow('src', im_cv)
cv.imshow('dst', dst)
cv.waitKey(0)
cv.destroyAllWindows()
這與使用 ImageMagick 中的Convert -implode函數具有相同的效果。
開滿天機
TA貢獻1786條經驗 獲得超13個贊
您可以使用 Python Wand（使用 ImageMagick）中的內爆和爆炸選項來完成此操作。
輸入：
from wand.image import Image
import numpy as np
import cv2
with Image(filename='zelda1.jpg') as img:
img.virtual_pixel = 'black'
img.implode(0.5)
img.save(filename='zelda1_implode.jpg')
# convert to opencv/numpy array format
img_implode_opencv = np.array(img)
img_implode_opencv = cv2.cvtColor(img_implode_opencv, cv2.COLOR_RGB2BGR)
with Image(filename='zelda1.jpg') as img:
img.virtual_pixel = 'black'
img.implode(-0.5 )
img.save(filename='zelda1_explode.jpg')
# convert to opencv/numpy array format
img_explode_opencv = np.array(img)
img_explode_opencv = cv2.cvtColor(img_explode_opencv, cv2.COLOR_RGB2BGR)
# display result with opencv
cv2.imshow("IMPLODE", img_implode_opencv)
cv2.imshow("EXPLODE", img_explode_opencv)
cv2.waitKey(0)
內爆：
爆炸：
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