使用canon_cr3库从.CR3文件获取未压缩的图像数据

Question

I want to convert a .CR3 file (camera is a Canon PowerShot SX70 HS) to a .PNG file using Python (another losless image format would be fine as well). I found a project on GitHub which should help to do the desired task: https://github.com/lclevy/canon_cr3

I'm able to load the .CR3 file as an Image object within the canon_cr3 library in Python. Hence, corresponding to the doc of canon_cr3 I can access the small definition raw image (track2) and the high definition raw image (track3). The code:

image = 'D:\pic\test.CR3'
image = image.replace("\\", "/") #working on Windows
img = Image(image)
sd_img = img.sd_crx_image
print(type(sd_img))
print(len(sd_img))
print(sd_img[0:100])

yields

<class 'bytes'>
1536824
b'\xff\x01\x00\x08\x00\x17r\xc8\x00\x00'

The library contains several functions like tiff(...) . However, I cannot figure out how to apply these functions to store an uncompressed image or get the image information in Python (eg a Numpy array representing the image's pixels). I tried the following code which yields a .PNG file, however, it cannot be opened:

with open('D:/pic/test1.PNG', 'wb') as f:
    f.write(img.sd_crx_image)

Does anyone have an idea?

Answer 1

Once downloaded the canon_cr3-master.zip file from https://github.com/lclevy/canon_cr3 it comes with a file named parse_cr3.py . I realized that the file uses the OptionParser library to provide additional functions when running the script in the command prompt. Hence, entering the line

Python parse_cr3.py image.cr3 -v 1 -x

extracts the .JPG file and the small as well as high definition raw image in two .crx files (trak2.crx and trak3.crx). I suggest that the .crx files can be opened in some way. However, I couldn't figure out so far how this is done.