I found this very nice example, how to make an array of frames: https://stackoverflow.com/a/17394994/7489698
But I do not know how to use this in PIL correctly. To demonstrate it, I have sketched this commands:
import numpy as np
import cv2
from PIL import Image, ImageTk
nframes = 10
frame = cv2.imread('test.jpg')
(x,y,d)=frame.shape
frames = np.empty((nframes,x, y, d))
for k in range(nframes):
frames[k,:,:,:] = frame
frame_avg=np.int8(np.mean(frames,0))
frame_avg.shape
cv2.imwrite('test_avg.jpg',frame_avg)
Image.fromarray(frame)
Image.fromarray(frame_avg)
The image test.jpg is read and 10 times stored in the array frames. The average thereof is stored in the file test_avg.jpg where it can be seen that it looks ok.
Converting the orignal frame to a PIL image is working, but the last line throws this error:
---> 20 Image.fromarray(frame_avg)
/usr/local/lib/python3.10/dist-packages/PIL/Image.py in fromarray(obj, mode)
3313 typekey_shape, typestr = typekey
3314 msg = f"Cannot handle this data type: {typekey_shape}, {typestr}"
-> 3315 raise TypeError(msg) from e
3316 else:
3317 rawmode = mode
TypeError: Cannot handle this data type: (1, 1, 3), |i1
What did I do wrong???
KR, Christof
The frame_avg array you created has a data type of int8 (|i1), which PIL's Image.fromarray does not support for RGB images. PIL expects uint8 (np.uint8) data for typical RGB images. That's why you are seeing the TypeError. Change the data type of frame_avg from int8 to uint8. And edit your code like this:
import numpy as np
import cv2
from PIL import Image
nframes = 10
frame = cv2.imread('test.jpg')
# Convert to RGB for PIL compatibility (OpenCV reads as BGR)
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
(x, y, d) = frame.shape
frames = np.empty((nframes, x, y, d), dtype=np.uint8)
for k in range(nframes):
frames[k, :, :, :] = frame
# Average and convert back to uint8
frame_avg = np.mean(frames, axis=0).astype(np.uint8)
# Save averaged image using OpenCV (convert back to BGR for OpenCV)
cv2.imwrite('test_avg.jpg', cv2.cvtColor(frame_avg, cv2.COLOR_RGB2BGR))
# Convert to PIL Image and display
Image.fromarray(frame) # should work
Image.fromarray(frame_avg) # now works too
The following documentations and links may help you
Which is best practice doing null checks or empty checks with Kotlin data classes?
https://github.com/python-pillow/Pillow/issues/1190
https://pillow.readthedocs.io/en/stable/reference/Image.html#PIL.Image.fromarray
If you are looking for some more OpenCV related projects, you can see here: https://www.pcbway.com/project/shareproject/How_to_use_AI_to_program_a_2DOF_ROBOT_Arduino_pyhton_opencv_chatgp_ps3eyecam_d3896679.html