Re: Acquiring Dental RVG on Linux

[Sonali Warunjikar <sonali.warunjikar@gmail.com>]

On Thu, Dec 31, 2020 at 01:10:25PM -0500, Aaron M. Ucko wrote:
> From what I gather, python3-pythonmagick should support 16-bit channel
> depths.  I'm not at all familiar with its usage details, though, so I
> can't give you any more specific tips.

In the meantime I used libpng. It supports 16 bit depth. But the results
aren't yet correct - it's not looking like a normal X ray. May be I am
missing something about the image format.

I am keeping a sample image if anyone could try and reconstruct here:
http://mayuresh.sdfeu.org/img.dat.gz

Note the parameters:

width = 1168
height = 1562
depth = 16

It's little endian or big endian is unclear, both ways it is producing
results.

interlace is true or false is not clear, pypng did not show any difference
when interlace in its png encoder was true vs false.

It may require color inversion, which could be done either after
reconstructing image or during.

Here is some code using pypng:

# Please set flnm suitably
import struct
with open(flnm,'rb') as fp: buf = [ 65535 - v[0] for v in struct.iter_unpack('>H',fp.read()) ]

width = 1168
height = 1562
depth = 16
arr = [ buf[i:i+width] for r in range(height) for i in [r*width] ]

import png 
with open('see.png','wb') as fp: 
    png.Writer(
        width = width,
        height = height,
        greyscale = True,
        bitdepth = depth,
        ).write(fp,arr)