Reading and saving 12bit Raw bayer image using OpenCV / Python-CodePudding

I'm trying to read and save a 12bit Raw file using Python and openCV. The code I'm using saves an image but the saved image is garbled / distorted.

The image is from a FLIR Oryx Camera 23MP (5320x4600) 12Bit with BayerRG12P pixelformat, which should be RG GB bayer pattern.

import cv2
import numpy as np

width = 5320
height = 4600

with open("aaa12packed.Raw", "rb") as rawimg:
   img = np.fromfile(rawimg, np.dtype('u1'), width * height).reshape(height, width)
   colimg = cv2.cvtColor(img, cv2.COLOR_BAYER_GR2RGB)
   cv2.imwrite("test.jpeg", colimg)

I uploaded two raw files that I'm using to test the debayer/demoisaic. You can download them using the link below:

"RG12P.Raw" (this is the 12bit regular) and "RG12packed.Raw" (this is the 12bit packed)

CodePudding user response：

I'm not sure of the difference between the two files you shared, but here is a fairly speedy technique to read and unpack the 12-bit samples. I am not really sure what you actually want so I have put plenty of debug code and comments so you can see what I am doing then you can fine-tune.

Don't be put off by the length of the code, there are only really 4 lines which I have numbered in comments:

#!/usr/bin/env python3
# Demosaicing Bayer Raw image

import cv2
import numpy as np

filename = 'RG12P.Raw'

# Set width and height
w, h = 5320, 4600

# Read entire file and reshape as rows of 3 bytes
bayer = np.fromfile(filename, dtype=np.uint8).reshape((-1,3))    # LINE 1
print(f'DEBUG: bayer.shape={bayer.shape}')
for i in 0,1,2:
   print(f'DEBUG: bayer[{i}]={bayer[i]}')

# Make each 3-byte row into a single np.uint32 containing 2 samples of 12-bits each
bayer32 = np.dot(bayer.astype(np.uint32), [1,256,65536])         # LINE 2
print(f'DEBUG: bayer32.shape={bayer32.shape}')
for i in 0,1,2:
   print(f'DEBUG: bayer32[{i}]={bayer32[i]}')

# Extract high and low samples from pairs
his = bayer32 >> 12                                              # LINE 3
los = bayer32 &  0xfff                                           # LINE 4

print(f'DEBUG: his.shape={his.shape}')
for i in 0,1,2:
   print(f'DEBUG: his[{i}]={his[i]}')

print(f'DEBUG: los.shape={los.shape}')
for i in 0,1,2:
   print(f'DEBUG: los[{i}]={los[i]}')


# Stack into 3 channel
#BGR16 = np.dstack((B,G,R)).astype(np.uint16)

# Save result as 16-bit PNG
#cv2.imwrite('result.png', BGR16)

Sample Output

DEBUG: bayer.shape=(12236000, 3)
DEBUG: bayer[0]=[119 209  36]
DEBUG: bayer[1]=[249  17  29]
DEBUG: bayer[2]=[ 49 114  35]
DEBUG: bayer32.shape=(12236000,)
DEBUG: bayer32[0]=2412919
DEBUG: bayer32[1]=1905145
DEBUG: bayer32[2]=2322993
DEBUG: his.shape=(12236000,)
DEBUG: his[0]=589
DEBUG: his[1]=465
DEBUG: his[2]=567
DEBUG: los.shape=(12236000,)
DEBUG: los[0]=375
DEBUG: los[1]=505
DEBUG: los[2]=561