Workflow for linear dng files

[pierrelabreche]

A Samsung Galaxy S22 can shoot in Expert RAW mode. This produces excellent images in linear DNG and jpeg formats.

Refer to https://www.samsung.com/levant/support/ ... t-raw-app/

However, my attempts at processing these linear Dng files using PWP produce so-so results.

Question open to all, what is your highest quality workflow to process linear DNG files using PWP. ?

[den]

My initial S22 linear DNG file conversion workflow [sRGB working/display color space and 2.20 gamma]:
1. Convert the DNG file to your working and display color space (sRGB);
2. Linearly expand to white (255) and black (0) points;
3. Apply an Inverse 2.20 gamma curve;
4. Correct white/black points for color balance; and
5. Lightly sharpen for small, medium, and large detail.

LinearDNG_File.JPG (153.74 KiB) Viewed 1766 times

Attached is a workspace script (in ".txt" format for posting) for the above steps in the HSV, HSL, and RGB color spaces.

The resulting image(s) is/are suitable for further tone/color mapping according image content and artistic preferences.

The images are somewhat flatt but contain all available file tone/color/detail.

Mostly I will use the resulting RGB image for my preference tone/color mapping to the final image.

...den...

[pierrelabreche]

Hi Den

I get an error when loading the workspace script.
Could you check it and also post a plain script file for the end image (s)

What is an inverse gamma curve and why ?


Many thanks

Pierre

[den]

Pierre...

It has been too long since I've edited a script to know what is specific to my files/system so I will post pictures of the RGB branch from which it is simple to form your own script.

Step 1. An Expanded histogram RGB-All Color Curves transform in which the upper right control point is moved left to the histogram edge and if necessary the bottom point is moved to the right.

Step 1 RGB-All Expanded Histogram.JPG (86.67 KiB) Viewed 1733 times

Step 2. An Inverse 2.20 gamma brightening curve is applied using an RGB-All Color Curves transform.

Step 2 RGB-All Inverse 2.20 Gamma Curve Expanded Histogram.JPG (88.9 KiB) Viewed 1733 times

Step 3. The black/white point color casts are removed using the Multi-Color Balance transform.

Step 3 Remove Black-White points color cast.JPG (82.99 KiB) Viewed 1733 times

Continued in next post...

[den]

Continued....

Step 4. Light sharpening is applied using the Multi-Sharpening transform with Pass 1, R=50; Pass 2, R=5; and Pass 3, R=2.

Step 4 Sharpen Pass1 R=50 Pass2 R=5 Pass3 R=2.JPG (121.98 KiB) Viewed 1733 times

For why an Inverse 2.20 gamma assuming you have a LCD sRGB display, see: https://www.eizo.com/library/basics/lcd_display_gamma/

...den...

[pierrelabreche]

Hello Den,

Thank you very much, your workflow is very clear !

[den]

...
I recently upgraded to Expert Raw v3.0.08.10 for my Galaxy S22 camera phone and PWP8 will no longer open the linear *.dng file and produces an error message: "Error reading file: C:\... \...\20241002_112201.dng".

Also, the linear *.dng file cannot be read by Raw Therapee v5.11 or Dark Table v4.8.1.

A work around is using Adobe DNG Converter v17.0, changing the Preferences/Compability to "Camera Raw 14.0 and later".

So that the converted file is recognizable, change "File extension:" to " .DNG" if it is to be saved in the same folder as the original.

CaptureAdobeDNGConverter-1.jpg (65.39 KiB) Viewed 1300 times

This seems to be a Samsung\Windows related problem awaiting resolution...

Have fun... ...den...

[den]

...
There seems to be further interest in this thread so a typical workflow for me is:
1. Create a converted .DNG file and perform the previous described/illustrated steps.
2. Create plus/minus exposures using PWP8's Color Curves RGB-All curves transform.
3. Import the exposures to SNS-HDR (https://sns-hdr.com) for image merging and tone-mapping.
4. Export the blended/tone-mapped image to PWP8 for final processing including: vibrance saturation; color-balance; crop for composition; and sharpen.

An example: a winter's view of Birch Point and northern Canadian Cascades as viewed from Point Whitehorn, Birch Bay, WA USA.

20241209_143612_1_DNG v1.jpg (117.41 KiB) Viewed 745 times

For comparison: the jpg camera version.

20241209_143612 jpg v1.jpg (113.48 KiB) Viewed 745 times

Again have some fun... ...den...