How to covert negative images to positive images

[ajgreeny]

Are these negative images actual photographic negatives that you've scanned and want to invert to positives for printing or just to archive the pictures?

I have tried many times to do that with some old B/W negatives and some 35mm slides but never managed to get anything to work well enough so I suspect it may need a dedicated negative scanner.
Alternatively, though I've not tried this myself, try scanning using a backlit screen placed over the negative to ensure enough white light is passing through the negative as it sits on the scanner.
Perhaps that is what you did already when you said " Use a 12" tablet as light box"?

[dragonfly41]

I have this very old, ancient, scanner which I have never applied to my old 35mm film and slides which go back to last century. I might reawaken interest. However it requires my dual boot Windows to run the scanner.

https://support.usa.canon.com/kb/s/a...s%20obstructed.

[qyot27]

In AviSynth:

ImageSource("%03d.png", start=1) # image sequence 001.png, 002.png, 003.png ...
Invert()

[HermanAB]

The problem is that a scanned negative film is not a simple mathematical inverse of a positive photo, and no matter how much you play with Hue and Tint, you won’t get it right. I have only ever managed to convert film to B&W and Sepia tones with acceptable quality.

I think you will need something very smart to do the conversion. The Wolfram suggestion is probably the way to go.

[satimis]

In GIMP, it's in the Colors menu.
Open the image file, then
Colors > Invert

Hi Dennis,

Thanks for your advice.

That was what I did in the past. The quality of the postive image is still poor, similar to running 'convert" command on Terminal;

$ convert negative.jpg -negate positive.jpg

Further adjusting is needed. I used Color -> Curve

But I have hundreds of negatives. I'm trying finding an easier solution. I don't mind converting them one-by-one.

Regards

[dragonfly41]

But I have hundreds of negatives. I'm trying finding an easier solution. I don't mind converting them one-by-one.

Here is another automation plan.
(1) Install Recoll
(2) Let Recoll index your entire desktop and devices (go away and leave it running for a long time on first usage)
(3) Return after indexing completed and open the Recoll GUI
(4) In query field type [ext:jpg] - meaning show all files with extension .jpg
(5) Sort the files as you wish to plod through them
(6) If your cursor hovers over query field you will see a popup giving examples of complex queries
(7) Select the *.jpg you wish to process.
(8) Right click and you see multiple options

Now it becomes interesting.

You might wish to apply a custom script to different file types.

For this automation customisation go to [Preferences] in Recoll topbar.

[GUI configuration].

[User Interface tab] > [Choose Editor Applications] > [Native Viewers].


In long list look for Mime Type [image/jpeg]

Untick: [Use Desktop preferences by Default]

e.g. image/jeg has command [ristretto %f] associated.

This gives you an opportunity to substitute default command with your own custom script (ending in %f which means use the selected file from Recoll index).

Now all options are open and I will not go so far as exploring how to apply say a custom Python script to selected MIME type.

For example I map:

MIME Type Command
application/pdf masterpdfeditor %f

So "pair" MIME type with an application such as Gimp, ImageMagick, Wolfram and apply to the image you select in Recoll GUI.

Recoll is an ingenious tool.


I use it to index and open CherryTree notes such as:

application/xml cherrytree %f


Having written above I see that MIME type *.jpg does not open in Recoll (only jpeg is listed) so you will need to add a new value image/jpg with associated viewer/script.


[FOOT NOTE]

As an additional refinement you can use Recoll to display all of your hundreds of images in a search profile. Test the process first. Then the rabbit out of a hat trick is to move to another smart tool Actiona to progress automatically through every image one by one by emulating the keyboard and mouse actions. Sit back and watch it running through your images like a movie by controlling Recoll as a target window in Actiona. This "image factory" workflow might also use Albert as previously discussed, where Albert drives Actiona whch in a chain drives Recoll ... ... and Wolfram if you take that step.

[satimis]

Here is another automation plan.
(1) Install Recoll
(2) Let Recoll index your entire desktop and devices (go away and leave it running for a long time on first usage)
(3) Return after indexing completed and open the Recoll GUI
(4) In query field type [ext:jpg] - meaning show all files with extension .jpg
(5) Sort the files as you wish to plod through them
(6) If your cursor hovers over query field you will see a popup giving examples of complex queries
(7) Select the *.jpg you wish to process.
(8) Right click and you see multiple options

Now it becomes interesting.

You might wish to apply a custom script to different file types.

For this automation customisation go to [Preferences] in Recoll topbar.

[GUI configuration].

[User Interface tab] > [Choose Editor Applications] > [Native Viewers].


In long list look for Mime Type [image/jpeg]

Untick: [Use Desktop preferences by Default]

e.g. image/jeg has command [ristretto %f] associated.

This gives you an opportunity to substitute default command with your own custom script (ending in %f which means use the selected file from Recoll index).

Now all options are open and I will not go so far as exploring how to apply say a custom Python script to selected MIME type.

For example I map:

MIME Type Command
application/pdf masterpdfeditor %f

So "pair" MIME type with an application such as Gimp, ImageMagick, Wolfram and apply to the image you select in Recoll GUI.

Recoll is an ingenious tool.


I use it to index and open CherryTree notes such as:

application/xml cherrytree %f


Having written above I see that MIME type *.jpg does not open in Recoll (only jpeg is listed) so you will need to add a new value image/jpg with associated viewer/script.


[FOOT NOTE]

As an additional refinement you can use Recoll to display all of your hundreds of images in a search profile. Test the process first. Then the rabbit out of a hat trick is to move to another smart tool Actiona to progress automatically through every image one by one by emulating the keyboard and mouse actions. Sit back and watch it running through your images like a movie by controlling Recoll as a target window in Actiona. This "image factory" workflow might also use Albert as previously discussed, where Albert drives Actiona whch in a chain drives Recoll ... ... and Wolfram if you take that step.

Hi dragonfly41,

Lot of thanks for your detail advice and time spent to help me.

I'll test Recoll on a VM of VirtualBox, because this is my daily work PC.


EDit
===
I found an old 128GB SSD. Can I use it for this test ?


Regards

[dragonfly41]

I have just come back to this thread. Regarding spending time on this don't worry since it has brought this up the stack of things I must do. I plan to use Recoll to index multiple MIME types to "get order out of chaos" in my desktop. to migrate multiple, multiple files into an Obsidian data vault. A constellation.

Now it is quite a good idea to place your archives into a 128GB SSD. You can then point Recoll to only that SSD and make it do its magic. In Recoll you can choose a specific location of the files to be indexed rather than the entire desktop (although if you do index the entire desktop you will find images buried away as say thunderbird email attachments and other hidden places). So desktop is wide scan, specific SSD is narrow scan. But remember that there must be headroom for Recoll to place its index which is large. Suggest that you read the Recoll forum since Python can be used as Recoll driver. This fits well with use of Albert python extensions. But this might be too much of a step for you.

One thread in forum: https://www.freelists.org/post/recol...oogle_vignette

RSS feed can also be installed in LifeRea.

Just to confuse further a few days ago I stumbled onto Adobe upload facility where you can upload and convert images into SVG. Free. Then the SVG code can be viewed in Inkscape and the colours in different fills (XML code) can simply be changed. I plan to experiment later with this idea .. much later. https://www.adobe.com/express/