04-22 06:28 阅读 141

opencv-python处理图片的一些列操作

cvtColor函数

这个函数有两个参数
1，src 要进行变换的原图像
2，code 转换代码标识
例子：

import cv2
image=cv2.imread("ddd.jpg")image1=cv2.cvtColor(image,cv2.COLOR_BGR2BGRA)cv2.imshow("",image1)cv2.waitKey(0)if __name__ == '__main__':print()

split()和merge()

例子：

import cv2
image=cv2.imread("ddd.jpg")# image1=cv2.cvtColor(image,cv2.COLOR_BGR2BGRA)r,g,b=cv2.split(image)cv2.imshow("r",r)cv2.imshow("g",g)cv2.imshow("b",b)cv2.waitKey(0)if __name__ == '__main__':print()

import cv2
image=cv2.imread("/home/dfy/Pictures/Camera_photo/Camera_photo/sss.jpg")# image1=cv2.cvtColor(image,cv2.COLOR_BGR2BGRA)r,g,b=cv2.split(image)cv2.imshow("r",r)cv2.imshow("g",g)cv2.imshow("b",b)image1=cv2.merge([b,g,r])cv2.imshow("image",image1)cv2.waitKey(0)if __name__ == '__main__':print()

threshold()函数

ret，image= cv2.threshold(src,thresh,maxval,type)
实现二值化的重要函数
参数说明
src 输入图像
image 输出图像
thresh 阀值
maxval 当像素值超过阀值thresh 时赋值为maxval
type 当像素值小于阀值thresh的时赋值为type type可填下面5种类型的参数
例子：

import cv2
image=cv2.imread("/home/dfy/Pictures/Camera_photo/Camera_photo/sss.jpg")# image1=cv2.cvtColor(image,cv2.COLOR_BGR2BGRA)# r,g,b=cv2.split(image)# cv2.imshow("",r)# cv2.imshow("",g)# cv2.imshow("",b)# image1=cv2.merge([b,g,r])# cv2.imshow("image",image1)ret,image1=cv2.threshold(image,127,255,cv2.THRESH_BINARY)ret1,image2=cv2.threshold(image,127,255,cv2.THRESH_BINARY_INV)# ret2,image3=cv2.threshold(image,127,255,cv2.THRESH_TRIANGLE)ret3,image4=cv2.threshold(image,127,255,cv2.THRESH_TOZERO)ret4,image5=cv2.threshold(image,127,255,cv2.THRESH_TOZERO_INV)cv2.imshow("1",image1)cv2.imshow("2",image2)# cv2.imshow("3",image3)cv2.imshow("4",image4)cv2.imshow("5",image5)cv2.waitKey(0)if __name__ == '__main__':print()

自定义threshold函数进行二值化

import cv2
image=cv2.imread("/home/dfy/Pictures/Camera_photo/Camera_photo/sss.jpg")width,height,n=image.shape
image2=image.copy()for i in range(width):for j in range(height):for channel in range(3):if image2[i][j][channel]>127:image2[i][j][channel]=255else:image2[i][j][channel]=0cv2.imshow('',image2)cv2.waitKey(0)if __name__ == '__main__':print()

这个速度很慢对于分辨率太高的图

色度函数applyColorMap

import cv2
image=cv2.imread("/home/dfy/Pictures/Camera_photo/Camera_photo/sss.jpg")image_color_map=cv2.applyColorMap(image,cv2.COLORMAP_JET)cv2.imshow("im",image_color_map)cv2.waitKey(0)if __name__ == '__main__':print()