Convert RAW from I'm Back into DNG

View the Project on GitHub shyrodgau/imbraw2dng

imbraw2dng - Convert RAW from I’m Back(R) into DNG

This is free software and not commercially supported.

In here: Installation - Internationalization - Usage - Processing the DNG - How does it work - Browsing on the ImBack


They are not really “B&W RAW” but actually the RAW sensor data that also contains the colour filtering. You can see it when you import them as RAW into photoshop as Samuel described - zoom in and you see the gray values rastered in 2x2 squares. So even for B&W it is better to go the DNG way. The page can do parts (or partially more) of the mobile phone app.

Currently known to work for current firmware on 35mm (also for “Angle medium” and “small”) and MF I’m Back. Not all angle variants are covered for MF, if you need it and can help contact me.

Problems and ideas can also be discussed in the I’m Back Users Group on Facebook.


The current release is V2.9.9_c82b5e1 - Experimental for Imback Wifi .

Copy the imbraw2dng.html file to your PC or extract it from the release “Source code”.zip or .tar.gz and open in your favorite browser (any newer one should do).

If you can not install it locally, you can use it from the network like on my github page (should always be current version) or at (with automated translation to different languages, but might not be current). The image data will stay in your browser in any case.

The github repository itself can be found here.


The current supported langauges are english (EN) and german (DE). If you save the html file with a name change to imbraw2dng_XX.html where XX is the language shortcut, it will open the page directly in that language.


You can drop all files from the I’m back into the blue field. It will then copy all non-RAW files exactly and convert the RAW files to DNG, replacing the .raw/.RAW file extension with .dng. When you use the Choose Files button, you can select RAW files directly.

Your browser will download them according to its download settings, so it might pop up a dialog where to save it for each file if so configured, or throw all files into your Downloads directory if so configured , or, or, or…

Conversion to DNG currently sets the Timestamp Tags if the filename seems to be a reasonable I’m Back filename, and the OriginalRawFilename to the name of the RAW inputfile. That way you can name the DNG file whatever you like without losing any of the original information.

New: you can do a step-by-step walk with a preview of the raw file. For that, check the Single Step with preview checkbox. On each file, you can select if you want to process or skip it and also if this same action should be applied to the rest of your currently selected files. When you check the Add separate download link for each file checkbox, then the files can be downloaded again (after the download that will be done automatically in the processing). It may cost memory to keep all these so I do not do it any more by default - you can always select the file(s) simply again.

Browsing on the ImBack

You can put the html file (also renamed according to internationalization) on the micro-SD that is inside the ImBack, let’s say into the IMBACK directory. Then you connect your PC to the ImBack Wifi and browse your Imback (or with the changed name).

It offers you direct processing/copying of files newer than a given timestamp, or you can use the visual browser to look at the files on the ImBack by type and/or date. RAW and JPEG images will be displayed. You can select files for processing/conversion or deletion.

Processing the DNG

Use your favourite software, e.g. darktable, lightroom, ufraw, rawtherapee etc.

Do not expect the image to be okay out-of-the-box. I will probably not be able to provide all tags in the DNG to satisfy all possible programmes. Take your time to adjust the colours and then the rest. If anyone is experienced around DNGs or knows someone who would be willing to help - please get in contact e.g. on Discussion on for Darktable/RawSpeed or I’m Back digital back Developers Group on Facebook.

A strong green or magenta tint all over the image should not happen any more! But if you have one and can not level it out using your software’s color matrix/color calibration or white-balancing, a sample image might be interesing to fix it.

Word on colours: The right way to get the colours correct is to adjust the color calibration or color matrix. I am trying to get this right somehow inside the DNG but I am far from it (in darktable, I can tell it to automatically set it for DNGs from maker ImBack). Do NOT use the default identity matrix but change the green/green value to something around 0.6..0.7. This will at first make the image look reddish with the (wrong) default white balance. But then you can use the white balance to adjust it correctly. It is much harder or impossible to get the white balance sorted out with identity color matrix! Sample darktable pictures of how the matrix and the white balance on near neutral light should look:

darktable sample color matrix green darktable sample neutral white balance

If a red highlighted spot is in the center of the image, a manual retouche after the processing is required, or use the following darktable setting, placing and sizing a circle shape manually around the area.

To avoid the red spot from the start, use a bigger aperture (smaller f-number) or combine the standard PDLC matte with a Fresnel screen from I’m Back or a Canon EG-xxx screen.

darktable sample agains red circle

How does it work?

DNG is a TIFF-like format and consists mainly of constant data around the original image scanlines. The data varies depending on width, height (they are noted explicitly and there are a lot of offsets depending on the data length) and filename (for the OriginalRawFilename tag) of the image. If the date from the ImB filename looks valid, tags (EXIFTAG_DATETIMEORIGINAL, TIFFTAG_DATETIME) are added for that. If it is from a MF ImB then the Color Filter Array is different.