使用OpenCV和Python编写图像的难度

我使用下面的代码从一个文件夹中读取多个图像，从所有图像中获取特定的裁剪，并在最后写入它们。裁剪部分似乎不起作用，这意味着裁剪部分无法写入

# import the necessary packages
import cv2
import os, os.path


#image path and valid extensions
imageDir = "C:\\Users\\Sayak\\Desktop\\Training\\eye\\1" #specify your path here
image_path_list = []
valid_image_extensions = [".jpg", ".jpeg", ".png", ".tif", ".tiff"] #specify your vald extensions here
valid_image_extensions = [item.lower() for item in valid_image_extensions]

#create a list all files in directory and
#append files with a vaild extention to image_path_list
for file in os.listdir(imageDir):
    extension = os.path.splitext(file)[1]
    if extension.lower() not in valid_image_extensions:
        continue
    image_path_list.append(os.path.join(imageDir, file))

#loop through image_path_list to open each image
for imagePath in image_path_list:
    image = cv2.imread(imagePath)

    # display the image on screen with imshow()
    # after checking that it loaded
    if image is not None:
        cv2.imshow(imagePath, image)
    elif image is None:
        print ("Error loading: " + imagePath)
        #end this loop iteration and move on to next image
        continue
    crop_img = image[200:400, 100:300]
    cv2.imwrite('pic{:>05}.jpg'.format(imagePath), crop_img)

    # wait time in milliseconds
    # this is required to show the image
    # 0 = wait indefinitely
    # exit when escape key is pressed
    key = cv2.waitKey(0)
    if key == 27: # escape
        break
# close any open windows
cv2.destroyAllWindows()

---

我已经修改了上面发布的代码。问题在于cv2.imwrite（）中使用的字符串格式设置。第一个参数必须是文件应保存位置的绝对路径，但您的代码正在传入类似的内容。 jpg=>pic/home/ubuntu/Downloads/10_page.png.jpg。当我使用有效的文件名时，保存裁剪的图像根本没有问题

#loop through image_path_list to open each image
for i,imagePath in enumerate(image_path_list):
    image = cv2.imread(imagePath)
    # display the image on screen with imshow()
    # after checking that it loaded
    if image is not None:
        cv2.imshow(imagePath, image)
    elif image is None:
        print ("Error loading: " + imagePath)
        #end this loop iteration and move on to next image
        continue
    # Please check if the size of original image is larger than the pixels you are trying to crop.
    (height, width, channels) = image.shape
    if height >= 400 and width >= 300:
        plt.imshow(image)
        plt.title('Original')
        plt.show()
        crop_img = image[100:400, 100:400]

        # Problem lies with this path. Ambiguous like pic/home/ubuntu/Downloads/10_page.png.jpg
        print('pic{:>05}.jpg'.format(imagePath))

        # Try a proper path. A dirname + file_name.extension as below, you will have no problem saving.
        new_image = os.path.join(imageDir,'{}.png'.format(str(i)))
        cv2.imwrite(new_image, crop_img)
        plt.imshow(crop_img)
        plt.title('Cropped')
        plt.show()

---

什么是

裁剪部分似乎不工作

，是否有任何错误？或者根本不写入裁剪的图像？是的，根本不写入裁剪的图像。对不起，我不清楚那个部分。后编辑。然后请检查您传递给

cv2.imwrite（）

的路径是否有效？这是调试的基础，不是吗？如果没有写入文件，可能是因为权限或文件名不可靠导致文件写入失败，或者要写入的数据不正确。您有能力对此进行调试：打印文件名以检查其是否有效以及写入的路径是否具有写入权限，或者显示裁剪后的图像以确保其良好。应该教会人们调试，而不是编程。检查权限和文件名。没问题。