Allow for importing and exporting curves

[bbartlomiej]

Hi,

in line with other editing software I'd like to have a way to import and export curves. I have some computed curves for digital negatives reversal and would like to import them into Affinity photo. Trying to match the shape of the curve does not provide proper results.

[SantaFeCam]

I second this request. In order for a switch to Affinity Photo to be useful to me, I need the ability to import Photoshop .acv files that I've used for many years, as presets to be used in Affinity Photo.

[PatrickMarq]

I support this also, as I need this also for my digital negatives

[Ruzeen]

I would like this also. There's a few curve presets I use for astrophotography which I would like to poll over to Affinity Photo since I've finished my transition from Photoshop to Affinity.

[John Rostron]

You can record a macro which will add a new Curves Layer, then adjust the parameters to you requirements.

John

[bbartlomiej]

33 minutes ago, John Rostron said:

You can record a macro which will add a new Curves Layer, then adjust the parameters to you requirements.

John

Thanks, but that's not what this is about. We want to be able to specify the curve manually in a text editor using numbers (as for PhotoShop, GIMP) and import this file in Affinity curves.
I have computational curves I'd like to use. Others would also like to backup and restore curves. This feature is available in almost all editing software so would be nice to have it in Affinity as well.

[SantaFeCam]

3 hours ago, bbartlomiej said:

This feature is available in almost all editing software so would be nice to have it in Affinity as well.

Agreed...though for me, it wouldn’t just be nice, it’s necessary. I was supplied .acv curves for my work that took someone else hours to develop through printing trials. Much as I’d like to, it doesn’t make sense for me to switch to a software that requires all that work to be redone. Digital negatives require curves that aren’t based on the visual appearance of the image, but rather the amount of UV light blocked by the pigment printed at each pixel on the negative. So the curves must be specified using coordinates, and as bbartlomiej said, it doesn’t appear Affinity provides for that.

[antimattr]

On 1/11/2021 at 9:15 AM, SantaFeCam said:

Agreed...though for me, it wouldn’t just be nice, it’s necessary. I was supplied .acv curves for my work that took someone else hours to develop through printing trials. Much as I’d like to, it doesn’t make sense for me to switch to a software that requires all that work to be redone. Digital negatives require curves that aren’t based on the visual appearance of the image, but rather the amount of UV light blocked by the pigment printed at each pixel on the negative. So the curves must be specified using coordinates, and as bbartlomiej said, it doesn’t appear Affinity provides for that.

Wow.  I have the exact same need!  I am working on a cyanotype process and need to import ACV curves and was really disappointed that it wasn't an option in Affinity.  I am not sure what to do right now.  I can delay my project for a while I guess, but if this isn't going to be added I need to find an alternative.

[bbartlomiej]

Unfortunately v2 haven't brought any changes in this area. Affinity - kindly add this simple enhancement to the curves tool.

[aldusmanutius]

It's 2024... has there been any changes in this? We alternative/historical photo process practitioners (say that quickly 3x!) really could use this and sooner rather than later. I have completely left the Adobe environment and, while GIMP is not my first choice, it does allow this functionality.

Affinity/Serif, please consider adding this feature. Thanks!

[Largo Lagrande]

If you guys still own Photoshop, you can use it to convert the .acv file to a .cube LUT file. And then import the LUT file in Affinity Photo !

Here are the steps required to convert an .acv file to a .cube LUT file in Photoshop :

1. Import the .acv File into Photoshop:

   • Open Photoshop.
   • Open a new image or create a blank file.
   • Apply the .acv file using the Curves Adjustment Layer.
     • Click on Layers > New Adjustment Layer > Curves and load the .acv file using the load option within the curves adjustment.

2. Export the LUT:

   • With the curves applied to the image, go to File > Export > Color Lookup Tables.
   • Choose the file format as .cube.
   • Save the LUT file.
   • For a detailed description about how the export dialog options work, please read https://helpx.adobe.com/photoshop/using/export-color-lookup-tables.html

Now to apply the .cube LUT file to an image in Affinity Photo, follow these steps :

1. Open Your Image in Affinity Photo:

   • Launch Affinity Photo and open the image you want to work on by navigating to File > Open, and selecting your image file.

2. Add an Adjustment Layer for the LUT:

   • In the Layers panel (usually located on the right side of the workspace), click the Adjustments icon (a circle split into black and white halves).
   • From the dropdown list, choose LUT. This will add a LUT adjustment layer on top of your image.

3. Import the .cube LUT File:

   • Once you’ve selected the LUT adjustment, a new window will appear for the LUT settings.
   • Click the Load LUT button, which allows you to browse and select a .cube file from your computer.
   • Navigate to the folder where your .cube LUT file is located and select it.

4. Apply the LUT to Your Image:

   • After loading the .cube file, the LUT will be applied to your image immediately.

That’s it! Your LUT is now applied to your image, and once inverted, bam! you have your digital negative ready to be printed !