使用 CV2 为图像添加光晕效果

Question

我目前正在后端使用 CV2 开发一个简单的照片编辑器，我想知道是否可以使用 CV2 向图像添加 bloom effect。

感谢您的帮助！

Answer 1

可以在Python/OpenCV实现bloom效果如下：

 - Read the input
 - Convert to HSV colorspace as floats and separate channels
 - Invert the saturation channel and multiply with the value channel, since to find white, we need low saturation and high brightness
 - Blur the product and convert to 3 channels
 - Blend the blurred image with the original applying gain to the blurred image
 - Save the result

输入：

import cv2
import numpy as np

# read image
img = cv2.imread('barn.jpg')

# set arguments
thresh_value = 245  # threshold to find white
blur_value = 50     # bloom smoothness
gain = 6            # bloom gain in intensity

# convert image to hsv colorspace as floats
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV).astype(np.float64)
h, s, v = cv2.split(hsv)

# Desire low saturation and high brightness for white
# So invert saturation and multiply with brightness
sv = ((255-s) * v / 255).clip(0,255).astype(np.uint8)

# threshold
thresh = cv2.threshold(sv, thresh_value, 255, cv2.THRESH_BINARY)[1]

# blur and make 3 channels
blur = cv2.GaussianBlur(thresh, (0,0), sigmaX=blur_value, sigmaY=blur_value)
blur = cv2.cvtColor(blur, cv2.COLOR_GRAY2BGR)

# blend blur and image using gain on blur
result = cv2.addWeighted(img, 1, blur, gain, 0)

# save output image
cv2.imwrite('barn_bloom.jpg', result)

# display IN and OUT images
cv2.imshow('image', img)
cv2.imshow('sv', sv)
cv2.imshow('thresh', thresh)
cv2.imshow('blur', blur)
cv2.imshow('result', result)
cv2.waitKey(0)
cv2.destroyAllWindows()

结果：

使用 CV2 为图像添加光晕效果

Adding bloom effect to an image using CV2

python

opencv