[FIXED] Opencv Error while sending png images through pytesseract

Issue

I am using pytesseract for ocr and it works fine for jpg,jpeg and some png files but crashes on selected png files which are mobile screenshots Here is my code:

img = cv2.imread('test.png',cv2.COLOR_BGR2GRAY)
custom_config = r'--oem 3 --psm 6'
data=pytesseract.image_to_string(img, config=custom_config)
print(data)

The error generated is:

Traceback (most recent call last):
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site-packages/PIL/Image.py", 
 line 2992, in fromarray
 mode, rawmode = _fromarray_typemap[typekey]
 KeyError: ((1, 1, 3), '<u2')

 The above exception was the direct cause of the following exception:

 Traceback (most recent call last):
 File "/home/hkc/Documents/work/opencv/test.py", line 13, in <module>
 data=pytesseract.image_to_string(img, config=custom_config)
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site- 
 packages/pytesseract/pytesseract.py", line 423, in image_to_string
 return {
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site- 
 packages/pytesseract/pytesseract.py", line 426, in <lambda>
 Output.STRING: lambda: run_and_get_output(*args),
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site- 
 packages/pytesseract/pytesseract.py", line 277, in run_and_get_output
 with save(image) as (temp_name, input_filename):
 File "/usr/lib/python3.10/contextlib.py", line 135, in __enter__
 return next(self.gen)
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site- 
 packages/pytesseract/pytesseract.py", line 197, in save
 image, extension = prepare(image)
 File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site- 
 packages/pytesseract/pytesseract.py", line 171, in prepare
image = Image.fromarray(image)
File "/home/hkc/Documents/work/opencv/cv/lib/python3.10/site-packages/PIL/Image.py", 
line 2994, in fromarray
 raise TypeError("Cannot handle this data type: %s, %s" % typekey) from e
TypeError: Cannot handle this data type: (1, 1, 3), <u2

Solution

You can't use cv2.COLOR_BGR2GRAY with cv2.imread() because all the ones starting with cv2.COLOR_XXX are for use with cv2.cvtColor().

You need to use the ones starting with cv2.IMREAD_XXX with cv2.imread().

So, I guess you want:

img = cv2.imread('test.png',cv2.IMREAD_GRAYSCALE)

Answered By - Mark Setchell