PIL.Image，OpenCV，Numpy Image格式互相转换

Convert between Python tuple and list：

a = (1, 2)      # a is a tuple b = list(a)     # b is a list c = tuple(b)  # c is a tuple

Convert between Python tuple, list and NumPy 1D array

a = (1, 2)          # a is a tuple b = np.array(a)  # b is an numpy array c = tuple(b)       # c is a tuple a = [1, 2]          # a is a python array b = np.array(a)  # b is a numpy array c = list(b)          # c is a python list

Convert between NumPy 2D array and NumPy matrix

a = numpy.ndarray([2,3])   # create 2x3 arraym1 = numpy.asmatrix(a)   # does not create new matrix, m1 refers to the same memory as a m2 = numpy.matrix(a)      # creates new matrix and copies content b1 = numpy.asarray(m2)   # does not create array, b1 refers to the same emory as m2b2 = numpy.array(m2)      # creates new array and copies content

Read/Write Images with OpenCV

image = cv.LoadImage(“ponzo.jpg”)cv.SaveImage(“out.png”, image)

Read/Write Images with PIL

image = Image.open(“ponzo.jpg”)image.save(“out.jpg”)

Read/Write Images with PyOpenCV

mat = pyopencv.imread(“ponzo.jpg”)pyopencv.imwrite(“out.png”, mat)

Convert between OpenCV image and PIL image

# color image cimg = cv.LoadImage("ponzo.jpg", cv.CV_LOAD_IMAGE_COLOR)     # cimg is a OpenCV imagepimg = Image.fromstring("RGB", cv.GetSize(cimg), cimg.tostring())    # pimg is a PIL image cimg2 = cv.CreateImageHeader(pimg.size, cv.IPL_DEPTH_8U, 3)      # cimg2 is a OpenCV image cv.SetData(cimg2, pimg.tostring())Note: OpenCV stores color image in BGR format. So, the converted PIL image is also in BGR-format. The standard PIL image is stored in RGB format. # gray image cimg = cv.LoadImage("ponzo.jpg", cv.CV_LOAD_IMAGE_GRAYSCALE)   # cimg is a OpenCV image pimg = Image.fromstring("L", cv.GetSize(cimg), cimg.tostring())                 # img is a PIL image cimg2 = cv.CreateImageHeader(pimg.size, cv.IPL_DEPTH_8U, 1)              # img2 is a OpenCV imagecv.SetData(cimg2, pimg.tostring())

Convert between PIL image and NumPy ndarray

image = Image.open(“ponzo.jpg”)   # image is a PIL image array = numpy.array(image)          # array is a numpy array image2 = Image.fromarray(array)   # image2 is a PIL image

Convert between PIL image and PyOpenCV matrix

image = Image.open(“ponzo.jpg”)                  # image is a PIL imagemat = pyopencv.Mat.from_pil_image(image)  # mat is a PyOpenCV matrix image2 = mat.to_pil_image()                        # image2 is a PIL image

Convert between OpenCV image and NumPy ndarray

cimg = cv.LoadImage("ponzo.jpg", cv.CV_LOAD_IMAGE_COLOR)   # cimg is a OpenCV image pimg = Image.fromstring("RGB", cv.GetSize(cimg), cimg.tostring())  # pimg is a PIL image array = numpy.array(pimg)     # array is a numpy array pimg2 = cv.fromarray(array)    # pimg2 is a OpenCV image

还可以这样子使用：
PIL.Image转换OpenCV格式：

import cv2  from PIL import Image  import numpy  image = Image.open("plane.jpg")  image.show()  img = cv2.cvtColor(numpy.asarray(image),cv2.COLOR_RGB2BGR)  cv2.imshow("OpenCV",img)  cv2.waitKey()  

OpenCV转换PIL.Image格式：

import cv2from PIL import Image  import numpy  img = cv2.imread("plane.jpg")  cv2.imshow("OpenCV",img)  image = Image.fromarray(cv2.cvtColor(img,cv2.COLOR_BGR2RGB))  image.show()  cv2.waitKey() 

参考资料：
1 http://www.mamicode.com/info-detail-1777172.html 2018.7.12
2 https://blog.csdn.net/u011534057/article/details/77529592/ 2018.7.12
3 https://blog.csdn.net/dcrmg/article/details/78147219 2018.7.12
4 https://blog.csdn.net/JohinieLi/article/details/81012572 2020.03.05