Color negative

[Jean-Luc]

I'm trying to subtract the orange mask from a color negative.
In PSP, there is no Subtract mode when using layers.
Using the Arithmetic Subtract doesn't produce a correct result.
Any clue?

I'm using the image found on this website:
https://suissexpress.wordpress.com/2016 ... -negatifs/
The owner says he is using Gimp and applying Difference mode. But Difference mode in PSP doesn't give the same result. I see on a screen capture Gimp has a Subtract mode. This mode is lacking in PSP.
The final image shown on this website is not good, in my opinion: magenta cast and whites are not white.

My first attempt:
Create a raster layer above the image.
Filling it with R202 G144 B132 (selected with Dropper tool between the holes in the bottom).
Make the image positive: Image / Negative image.
Layer with orange mask: Burn Mode + Opacity 79 and Merge Down.
Adjust / Color / Fade correction: 50.
Histogram Adjustment / Luminance / Gamma:0.76. OK.
Histogram Adjustment reset.
Histogram Adjustment / Colors:
Red / Gamma 1.36
Blue / Gamma 0.87
OK.
Adjust / Hue and Saturation / Vibrancy / Strength 35. OK.

My result:

[LeviFiction]

So this is kind of interesting.

I can confirm that difference works basically the same between PSP, GIMP, and Photoshop. I compared both GIMP and Photoshop equations, and did several tests to make sure they all came out about the same. Difference is simple it's the absolute value of one layer minus the other. C = |B-A| This makes it irrelevant which layer is on top and which is on bottom. They should always turn out the same.

This means that sampling the original image, and their resulting image I can tell you that they sampled color 204, 147, 136. Very close to what you got.

I then created a new image filled with just this color, and used image arithmetic, making sure the color image is Image1 and our negative is image2. I got the exact same results as I get with Difference.

[leahcimi]

The orange mask is created in the negative during processing in the Magenta & Cyan layers. The amount created is in inverse proportion to the amount of dye produced and its purpose is to compensate for the inperfections in the dyes. The overall effect is for a uniform 'inperfection' which can be corrected during printing. This means that the techinique of sampling the mask from between the sprokets & subtracting it from the image should work. The problem arises when the dyes in the Magenta & Cyan layers fade so that the 'inperfection' is no longer uniform but dependant on image content.

Splitting the image into CMY layers and applying some sort of saturation mask may help but I have not attempted this

Michael

[leahcimi]

I just tried something which produces slightly better results:
Image - Negative Image
Image - Split Channel - Split to CMYK
Adjust - One Step Photo Fix on each of the Cyan, Magenta, & Yellow images
Image - Combine Channel - Combine from CMYK
In the combine dialogue box, leave Cyan, Magenta, & Yellow as they appear but set the Black Channel Source to the Yellow image, then combine.

Better, but not perfect.

[Jean-Luc]

I then created a new image filled with just this color, and used image arithmetic, making sure the color image is Image1 and our negative is image2. I got the exact same results as I get with Difference.

Sorry for the misunderstanding.
The owner of the site says he used Difference. But using Difference in PSP produces artifacts (brown and blue, see attached).

I thought he was using Subtract. In Arithmetic mode, Subtract shows where the artifacts are present.

I'm trying to remove those artifacts.

[hartpaul]

I was able to use method 3 in this link
https://www.capturelandscapes.com/3-way ... photoshop/

1. Using Nik Color Efex Pro 4 > Remove Color Cast, use the Color slider as mentioned and the strength and then applt that.
2. In PSP Image > Negative Image which produces a faded image which looks oK.
3. Adjust > Color > Fade Correction
and finished after sharpening with this image.

[Jean-Luc]

I was able to use method 3 in this link

The result is good but I cannot reproduce your steps.
Do you apply Nik Color Efex on the negative? How do you see when it looks good?
If I apply the Nik filter on the positive image, I don't obtain your result.
Missing something?

[hartpaul]

I applied the Nik Efex to the color negative . Color 16 and Strength 100 % worked for me.

[Jean-Luc]

I applied the Nik Efex to the color negative . Color 16 and Strength 100 % worked for me.

I don't get the same result:

[JoeB]

I agree with Jean-Luc. Using PSP 2019 and following the steps you set out in your post I get the same result as Jean-Luc gets using the first (orange) negative image obtained from the OP's link.

[JoeB]

OK, I figured out which step @hartpaul forgot to mention in his steps. You first have to crop the original negative image so that you are only working with the image contents and not the border of the negative itself. So I first straightened the image, then selected only the image contents itself, cropped to selection, then applied his steps for the most part. I had Fade Correction set to 70. After that I applied Clarity at 50 percent then Unsharp mask at 2.00. Now I get the same results as @hartpaul.

[JoeB]

And now I also tried the same image but instead of Nik Color Efex I started with Perfectly Clear, choosing the Perfect Color dropdown and selecting Fix Tint Color from the options. I didn't change any of the sliders. Then I applied the other steps I set out in my previous post (above). If you download both the image from my previous post and this one which used Perfectly Clear, and put this image above the first one as a layer, then you can turn off and on the visibility of this layer to do an easily visible comparison of the differences. The main one I see is that the image using Nik Color Efex has a slightly warmer (orange/reddish) cast while the Perfectly Clear attempt is cooler with less of that reddish tint. I think (but just my opinion) that the Perfectly Clear result is a bit better. But that would be a matter of personal preference. I like warmer colors for people shots, for example, but for this type of shot I'm partial to somewhat cooler colors. Kodak film used to give a warmer result than Fuji (generally preferred for slides by many) in the old days. So I guess the Nik result would be more Kodak and the Perfectly Clear more Fuji.

[Jean-Luc]

OK, I figured out which step @hartpaul forgot to mention in his steps. You first have to crop the original negative image so that you are only working with the image contents and not the border of the negative itself.

Thank you JoeB.
I get it now...

I'm still continuing to try with PSP tools without external plugins.
I'll post my result when done.

[Jean-Luc]

I think working without removing the orange mask pollutes the final result.

In Image Arithmetic, Subtract mode, I observed that lowering the Bias value reduces the artifacts. I reduced the value until no artifact was visible. At that moment, I realized the outside frame was no more black but white. It could be an indication for future settings : modify the Bias value until the frame becomes white (=it means the orange color cast is completely removed).

Create a raster image same size the original and filled with R204 G147 B136.

Apply Image Arithmetic like this:

Image / Negative image.

Adjust / Color / Fade Correction: 70.

Layers / New adjusment layer / Histogram / Colors.
For each color, drag the right cursor (white) to the left on the feet of the curve.
Tweak the Red and Blue values:
Red: Gamma 1.23
Blue: Gamma 0.74

Duplicate the image's layer, set Layer Mode to Multiply and Opacity: 38.

Multiply.jpg (11.92 KiB) Viewed 2353 times

On top, add Layers / New adjustment layer / Local Tone Mapping / Strength 10.

On top, add Layers / New adjusment layer / Vibrancy / Adjustment 20.

Now the sunny day is rendered (shadows are sharp) and details are still visible in the railcars on the left. It is perhaps too much corrected but everyone can modify the values according to their tastes.

[JoeB]

As I look at this last result, Jean-Luc I find it quite a bit too orangy for my taste. Even the white buildings and the clouds are very tinted. Your lengthy process might have reduced the artifacts that you originally mentioned bothered you, but IMHO at the expense of the overall image looking less authentic to the way a daylight scene would have actually looked to the eye.