python OpenCV jpeg compression in memory
Question:
In OpenCV it is possible to save an image to disk with a certain jpeg compression. Is there also a way to do this in memory? Or should I write a function using cv2.imsave() that loads the file and removes it again from disk? If anyone knows a better way that is also fine.
The use case is real-time data augmentation. Using something else than OpenCV would cause possibly unnecessary overhead.
Example of desired function im = cv2.imjpgcompress(90)
Answers:
You can use imencode:
encode_param = [int(cv2.IMWRITE_JPEG_QUALITY), 90]
result, encimg = cv2.imencode('.jpg', img, encode_param)
(The default value for IMWRITE_JPEG_QUALITY is 95.)
You can decode it back with:
decimg = cv2.imdecode(encimg, 1)
Snippet from here
In OpenCV it is possible to save an image to disk with a certain jpeg compression. Is there also a way to do this in memory? Or should I write a function using cv2.imsave() that loads the file and removes it again from disk? If anyone knows a better way that is also fine.
The use case is real-time data augmentation. Using something else than OpenCV would cause possibly unnecessary overhead.
Example of desired function im = cv2.imjpgcompress(90)
You can use imencode:
encode_param = [int(cv2.IMWRITE_JPEG_QUALITY), 90]
result, encimg = cv2.imencode('.jpg', img, encode_param)
(The default value for IMWRITE_JPEG_QUALITY is 95.)
You can decode it back with:
decimg = cv2.imdecode(encimg, 1)
Snippet from here