Grain2Pixel: Free Photoshop Plugin to convert digitized Colour Negatives

With Grain2Pixel, all Adobe Photoshop users get a free plugin for converting previously digitized colour negatives. I have tried out this little tool and am publishing a step-by-step guide here. It actually worked pretty well for me.

Grain2Pixel offers very few settings options. This small program works almost automatically within Photoshop.

Here on my site there are already several ideas about negative converters – i.e. computer programs that can be used to convert orange color negatives in particular into color-accurate positives, preferably without a color cast. This is mainly relevant when digitizing films with a digital camera.

Theoretically, conversion is also possible with the “board tools” of a good image editing program. I myself have never been able to achieve the results that separate ‘tools’ (→ list of such programs) can deliver. Of course, this works without any problems with black and white films and slide films. For color negative films, however, I use special software.

For this article, I have now used the free add-on “Grain2Pixel” and converted some color negatives with it. Here is a short guide on how to do this. The program is apparently developed and provided by a single developer Bogdan – TheDude.

Website of Grain2Pixel

Only compatible with Photoshop CC

Initially, I immediately received an error message: The plugin is not compatible with my old CS6 Photoshop version. You actually need ‘Photoshop CC’ for this – i.e. the “normal”, current subscription version.

So I installed a trial version of Photoshop CC to try it out.

To call up as a Script

Then there is a special feature of Pixel2Grain: it is not a “real” plug-in but a ‘script’. It works very simply: you download the program from the website (scroll down a little if necessary) and unzip this zip file into a new folder in a place that you can easily remember – for example on your desktop. It obviously doesn’t matter whether you are working under Mac or Windows.

Next, open Photoshop:

Go to File › Scripts › Browse

You then open the “Grain2Pixel.jsx.bin”, which you had previously unpacked. You can also create an action for this process to shorten it a little. However, this is not necessary. Photoshop “remembers” the path to the last script file opened.

Even if this is technically a “script”, the article will also refer to it as an “add-on” or “plug-in”. It always means the same thing.

The small program window opens immediately afterwards:

Almost no Settings necessary

There are almost no settings to make at first. If Photoshop itself is very opulent, this little plug-in is not.

Continue with my instructions:

Select RAW Format

At the top (first arrow), you must first select what type of raw files you have: Are they RAW files or Tiff files?

You can also use Tiff files as a basis. For example, you can scan negatives with a scanner in ‘slide mode’ and then obtain negatives in Tiff format. RAW data (e.g. NEF files from Nikon or DNG files) work best.

Select Graphics

Next (second arrow), select the files to be converted.

several raw digitizations in a folder on my hard drive

You then navigate to the respective folder on the hard disk where the image files are located and select the desired ones. In Windows, you can hold down the CTRL key while selecting the desired images with the mouse. You can also select all or just one.

I also check the small box next to “Save in same Location”. This means that the converted images can then be found in a subfolder of the original folder (where the raw digitized images are located).

Do not use Umlauts

A note: In my case, the images could not be loaded as long as they were in a folder with umlauts in the name. You should therefore avoid using Üs and Ös etc. here – even in the file names themselves. I’m from Germany: We use a lot of umlauts.

Define Output Format

The output format can now be defined:

For a first test, I will leave the default settings as they are: The images are calculated in the space-saving JPG format. In my own practice, however, I would choose the Tiff format here. This is because such data can be edited better later (i.e. without banding).

Run – Start Script

Click on “Run” to start the script (third arrow). All previously selected raw files will now be converted.

Set Image Crop

But wait – first Pixel2Grain wants the cropping of the raw data to be defined:

This window appears. As you can see, I still have a black frame around my digitizations (these are the edges of my Negative carrier from photographing the negatives).

It makes sense to make the blue frame a little smaller so that only the actual motif is taken into account during further conversion. At the top of the Photoshop toolbar, you can set that the aspect ratio does not have to remain the same.

The Pixel2Grain default settings specify that the frame now defined applies to all images within the current mass conversion. However, this assumes that you have worked very cleanly during digitization or that the data is all in the same aspect ratio with the same margins.

However, if the raw data to be converted contains images with a different aspect ratio or with different margins, “Interactive Crop” must be selected under the Conversion Setup › Pre-Conversion › Chose crop method tab. Pixel2Grain then queries the frame separately for each image in the pass. The entire conversion process for all images can then of course no longer take place unattended.

And you can also completely deactivate the cutting away of frames and borders if you do this later in Photoshop anyway (e.g. with an action).

Automatic Color Filtering

Now comes one (last) message:

Grain2Pixel has now internally calculated a value for the white balance based on the first image. If all other raw data was previously digitized with the same (manual) camera settings, you can confirm this with “Yes”. The plugin then applies this to all other graphics in the batch.

However, if you used the digital camera in auto mode when digitizing or if you have a colourful mixture of digitized films, you should answer “No” here. Grain2Pixel then has to (re)calculate the white balance for each image separately. This then takes a little longer and with photographic series the results may not be uniform.

You should also sort the raw data for mass conversion (by film, format).

Now the Script is working

The script then works in front of itself. It will probably use various Photoshop tools and settings internally. I do not believe that an independent engine is at work here. There will certainly be complicated internal processes based on the regular Photoshop tools.

That’s about it

With my “normal” computer and my raw files with a resolution of 24 megapixels each, the process takes approx. 6 seconds per image file (frame and color settings were fixed, i.e. were not recalculated or corrected for each motif).

The graphics are then ready in a subfolder of the folder containing the raw data:

Example Photos

My sample photos were not subsequently changed in brightness and color (only in size). They were generated directly by Grain2Pixel:

Kitesurfer in the evening light

A boat is moored in a bay in the evening. Rain can be seen in the distance. The wind picks up.

Unfortunately, the “insider tip” was already full that afternoon.

In this motif, the mid-tones are a little too bright. But this can easily be corrected later in Photoshop.

As you can see, the conversion of the raw data (the digitized colour negatives) worked surprisingly well. I hadn’t really expected that.

Note: Under the Conversion setup › Conversion tab, you can set the “Color Cast Remove” option to “Smart” or “Extra” if the converted images have a color cast. I used the default setting (“None”) for my example photos.

The graphics are slightly cropped in the histogram. In other words, the black point and white point are very close to the target line. In contrast to the digitization of big laboratories, for example, the images do not appear too harsh, as is usual with many of these automatic solutions.

I also experimented a little here: If some margin is left, highlights and shadows were not clipped too much in my case. It’s worth testing something here.

However, not everything went so smoothly when I tried and tested it. On the left you can see a version of this motif with completely wrong colors and contrast. I had ticked a few boxes in the advanced functions (which I don’t really understand). So: I pressed the reset button in the main window (“About” tab) and converted the negative again using the standard settings. Look at this – I also got a color photo with logical colors, even if it is a bit too bright in the midtones, which can be easily corrected afterwards.

This rather extreme example also shows that color negative film can be processed in various directions (even in the darkroom), that there is no “neutral” solution here.

Website of Grain2Pixel

Conclusion

Grain2Pixel offers only a few setting options. Surprisingly, I immediately got good results with the predefined options for this tutorial. The plugin works well and it is also completely free.

Some settings in the “Conversion setup” submenu don’t mean anything to me. In particular, I would like to prevent highlights and shadows from being (slightly) clipped in the histogram. I would therefore like to have a “flat” filtering with a full tonal range as a basis for further manual processing steps. Because I like to adjust the contrast afterwards using a separate gradation curve within Photoshop. Some other tools, such as the ‘Negmaster’ Photoshop plugin, take this into account better.

Otherwise, it’s a really helpful and good little program from the modest developer TheDude. Unfortunately, you have to pay a monthly subscription fee to Adobe for Photoshop in order to use it. That’s why I prefer to use a program like ‘SmartConvert’ to convert my colour negatives, which you only pay for once and then have peace of mind.