I need to convert a DNG file to PNG using python. I found a post here how to convert DNG: Opencv Python open dng format
The code I tried:
#open dng and convert
import rawpy
import imageio
import os
os.chdir(r'C:\Path\to\dir')
path = r'path\to\file'
with rawpy.imread(path) as raw:
rgb = raw.postprocess()
rgb_img.save('image.png')
However, it spits out the following errors:
line 13, in <module>
rgb = raw.postprocess()
File "rawpy\_rawpy.pyx", line 887, in rawpy._rawpy.RawPy.postprocess
File "rawpy\_rawpy.pyx", line 790, in rawpy._rawpy.RawPy.dcraw_process
File "rawpy\_rawpy.pyx", line 438, in rawpy._rawpy.RawPy.ensure_unpack
File "rawpy\_rawpy.pyx", line 432, in rawpy._rawpy.RawPy.unpack
File "rawpy\_rawpy.pyx", line 936, in rawpy._rawpy.RawPy.handle_error
rawpy._rawpy.LibRawTooBigError: b'Image too big for processing'
Is there either an alternative to convert the DNG files, or a way to bypass this error?
Info from exiftool:
ExifTool Version Number : 11.88
File Name : DSCF0001.DNG
Directory : .
File Size : 1313 MB
File Modification Date/Time : 2022:08:24 12:06:31+01:00
File Access Date/Time : 2022:08:25 08:17:15+01:00
File Inode Change Date/Time : 2022:08:24 15:19:04+01:00
File Permissions : rwxrwxrwx
File Type : DNG
File Type Extension : dng
MIME Type : image/x-adobe-dng
Exif Byte Order : Little-endian (Intel, II)
Make : FUJIFILM
Camera Model Name : GFX 100
Preview Image Start : 115208860
Orientation : Horizontal (normal)
Rows Per Strip : 3000
Preview Image Length : 3011337
Software : FUJIFILM Pixel Shift Combiner 1.2.0.2 (Real Color + High Resolution mode)
Modify Date : 2022:08:24 12:06:29
Artist :
Subfile Type : Full-resolution image
Image Width : 23296
Image Height : 17472
Bits Per Sample : 16 16 16
Compression : JPEG
Photometric Interpretation : Linear Raw
Samples Per Pixel : 3
Planar Configuration : Chunky
Tile Width : 128
Tile Length : 96
Tile Offsets : (Binary data 341026 bytes, use -b option to extract)
Tile Byte Counts : (Binary data 198743 bytes, use -b option to extract)
Black Level : 256 255 256
White Level : 65535 65535 65535
Default Scale : 1 1
Default Crop Origin : 16 12
Default Crop Size : 23264 17448
Anti Alias Strength : 1
Best Quality Scale : 1
Opcode List 3 : WarpRectilinear, FixVignetteRadial
Rating : 0
Copyright :
Exposure Time : 1/125
F Number : 8.0
Exposure Program : Manual
ISO : 100
Sensitivity Type : Standard Output Sensitivity
Standard Output Sensitivity : 100
Exif Version : 0230
Date/Time Original : 2019:03:10 00:44:16
Create Date : 2019:03:10 00:44:16
Shutter Speed Value : 1/125
Aperture Value : 8.0
Brightness Value : 8.57
Exposure Compensation : 0
Max Aperture Value : 2.0
Metering Mode : Multi-segment
Light Source : Unknown
Flash : No Flash
Focal Length : 110.0 mm
Version : 0130
Internal Serial Number :
Quality : NORMAL
White Balance : Auto
Saturation : 0 (normal)
White Balance Fine Tune : Red +0, Blue +0
Noise Reduction : 0 (normal)
Fuji Flash Mode : Manual
Flash Exposure Comp : 0
Focus Mode : Manual
AF Mode : No
Focus Pixel : 2001 1501
AF-S Priority : Release
AF-C Priority : Release
Focus Mode 2 : AF-M
AF Area Mode : Single Point
AF Area Point Size : n/a
AF Area Zone Size : n/a
AF-C Setting : Set 1 (multi-purpose)
AF-C Tracking Sensitivity : 2
AF-C Speed Tracking Sensitivity : 0
AF-C Zone Area Switching : Auto
Slow Sync : Off
Picture Mode : Manual
Exposure Count : 1
Shadow Tone : 0 (normal)
Highlight Tone : 0 (normal)
Lens Modulation Optimizer : On
Grain Effect : Off
Color Chrome Effect : Off
Crop Mode : n/a
Color Chrome FX Blue : Off
Shutter Type : Electronic
Auto Bracketing : Unknown (6)
Sequence Number : 1
Drive Mode : Single
Drive Speed : n/a
Blur Warning : None
Focus Warning : Good
Exposure Warning : Good
Dynamic Range : Standard
Film Mode : F0/Standard (Provia)
Dynamic Range Setting : Manual
Development Dynamic Range : 100
Min Focal Length : 110
Max Focal Length : 110
Max Aperture At Min Focal : 2
Max Aperture At Max Focal : 2
Image Stabilization : Sensor-shift; Off; 0
Image Generation : Original Image
Image Count : 34
Flicker Reduction : Off (0x0002)
Faces Detected : 0
Num Face Elements : 0
Color Space : Uncalibrated
Focal Plane X Resolution : 5320
Focal Plane Y Resolution : 5320
Focal Plane Resolution Unit : cm
File Source : Digital Camera
Scene Type : Directly photographed
Custom Rendered : Normal
Exposure Mode : Auto
Focal Length In 35mm Format : 87 mm
Scene Capture Type : Standard
Sharpness : Unknown (3)
Subject Distance Range : Unknown (48)
Serial Number :
Lens Info : 110mm f/2
Lens Make : FUJIFILM
Lens Model : GF110mmF2 R LM WR
Lens Serial Number :
DNG Version : 1.4.0.0
DNG Backward Version : 1.1.0.0
Unique Camera Model : FUJIFILM GFX 100
Color Matrix 1 : 1.7191 -1.1 0.1278 -0.3574 1.1733 0.2076 -0.0002 0.0497 0.654
Color Matrix 2 : 1.6212 -0.8423 -0.1583 -0.4336 1.2583 0.1937 -0.0195 0.0726 0.6199
Analog Balance : 1 1 1
As Shot Neutral : 0.5644 1 0.5153
Baseline Exposure : -0.01
Baseline Noise : 1
Baseline Sharpness : 1.33
Linear Response Limit : 1
Camera Serial Number :
DNG Lens Info : 110mm f/2
Shadow Scale : 1
DNG Private Data : (Binary data 114927728 bytes, use -b option to extract)
Calibration Illuminant 1 : Standard Light A
Calibration Illuminant 2 : D65
Aperture : 8.0
Image Size : 23296x17472
Megapixels : 407.0
Preview Image : (Binary data 3011337 bytes, use -b option to extract)
Scale Factor To 35 mm Equivalent: 0.8
Shutter Speed : 1/125
Circle Of Confusion : 0.038 mm
Field Of View : 23.4 deg
Focal Length : 110.0 mm (35 mm equivalent: 87.0 mm)
Hyperfocal Distance : 39.81 m
Light Value : 13.0
There seems to be a limit of 2GB for the fully expanded in memory image. I don't mean the space your DNG requires on disk, I mean the following number:
ImageHeight * ImageWidth * NumberOfChannels * BytesPerSample
So it would be useful if you used exiftool to tell us those parameters, by clicking edit under your question and adding the output from:
exiftool YOURIMAGE.DNG
The limit is enforced in the variable imgdata.params.max_raw_memory_mb which is set to 2048 in the underlying libraw C code. I am not immediately sure how you could set that through the Python interface.
You may have some success converting it to a PNG or a TIFF with ImageMagick as follows:
magick YOURIMAGE.DNG converted.png
If that works, you could use wand which is a Python binding to Imagemagick.
You could try with ufraw maybe, along the lines of:
ufraw-batch --out-type=png --out-depth=16 --output=result.png YOURIMAGE.dng