TypeError: img data type = 17 is not supported

Question

I create red image and try to save it via cv2.imwrite

    import numpy as np
    import cv2

    RED = [0, 0, 255]
    IMAGE_SIZE = 100

    image = np.empty([IMAGE_SIZE, IMAGE_SIZE], dtype=type(RED))
    for i in range(IMAGE_SIZE):
        for j in range(IMAGE_SIZE):
           image[i, j] = RED

    cv2.imwrite("red.png", image)

But I get error

     File "C:/Users/Andrew/Desktop/Programms/image-processing-cource/Tracks.py", line 11, in save_image
cv2.imwrite(name, image)
    TypeError: img data type = 17 is not supported

How to fix it?

Thanks!

Solution

dtype = type(RED) gives you type list and not type int.

you need:

image = np.empty([IMAGE_SIZE, IMAGE_SIZE, 3], dtype=type(RED[0]))

Comments

[Warren Weckesser]

Why did you use dtype=type(RED) for image? type(RED) is a python list; using that makes image an array of python objects (and not an with a numeric type). Why not use, say, dtype=int?

[IvanovAndrew]

If I use dtype=type(int) (and RED = 200) then I will get the same error

[Warren Weckesser]

Ue dtype=int (not type(int)). Setting the dtype sets the data type of the elements of the array that you are creating.

[Warren Weckesser]

Also, if you are trying to create an array that holds RGB components, the shape should be (IMAGE_SIZE, IMAGE_SIZE, 3). E.g image = np.empty([IMAGE_SIZE, IMAGE_SIZE, 3], dtype=int). If you want the elements to be, say, 8 bit unsigned integers (a typical size for images), you would use dtype=np.uint8.