process_cmd example to fix MacOs gamma issue on XDR displays

[codingluke]

Is your feature request related to a problem? Please describe.

On my Mac Pro with a XDR Display, which can not change the Color Profile, the pasted PNGs where always very faded like this

I found out, that this Problem was also reported at the pngpaste repository
The solution of this Issue does not work for me, as it is not possible to set a custom Color profile for my specific XDR display.

Describe the solution you'd like

After many frustrated tests I came across this stackoverflow issue to correct gamma through ImageMagick. https://stackoverflow.com/a/49453874

I tried following config, which worked perfectly :)

      default = {
        process_cmd = "convert - -set gamma 0.4545 -",
      },

Maybe it would be helpful for others to have this as hint in the Readme?

Best and thanks for your work!

[hakonharnes]

Hi @codingluke,

I plan on rewriting the entire README with the next release. I'll add your workaround to the README then. For now, I think you should update your answer in the pngpaste repository with the workaround :)

[hakonharnes]

Reopening until I've added this to the readme so I don't forget.

[hakonharnes]

FYI: I'm working on replacing pngpaste with my own tool called pbctl (https://github.com/hakonharnes/pbctl). That should hopefully resolve this issue. I'll let you know when it's ready for testing.

[hakonharnes]

Hi @codingluke,

I believe this should resolve your issue. First, install pbctl:

brew install hakonharnes/tap/pbctl

Then, set the correct branch in your Neovim config:

return {
  "HakonHarnes/img-clip.nvim",
  branch = "feat/pbctl",
  event = "VeryLazy",
  opts = {
    -- add your config here
  },
}

Would love to know if that resolves your issue :)

[codingluke]

Hi @hakonharnes
I just tested it and can confirm that the gamma problem is solved <3

However, I found some strange issue. When pasting with PasteImage it is not saving the file. When drag n drop it, it works.
My config is:

return {
  {
    "HakonHarnes/img-clip.nvim",
    branch = "feat/pbctl",
    event = "VeryLazy",
    opts = {
      default = {
        relative_to_current_file = true,
        dir_path = "img",
        download_images = true,
        copy_images = true,
      },
      -- add options here
      -- or leave it empty to use the default settings
      filetypes = {
        markdown = {
          url_encode_path = true,
          template = "![$CURSOR]($FILE_PATH)",
          download_images = true,
        },
      },
    },
  },
}

[hakonharnes]

That's strange. I'm not able to reproduce the issue. Could you please try to copy an image and run this in the terminal?

pbctl paste > image.jpeg
file image.jpeg

pbctl types
pbctl status

Please post the output of pbctl types, pbctl status and file image.jpeg.

Also, in Neovim: Run :PasteImage, then the:ImgClipDebug command. Please attach the output of :ImgClipDebug (you can get the output with :mess).

[codingluke]

$ pbctl paste > image.jpeg

$ pbctl types
Item 0
  public.file-url

$ pbctl status
Pasteboard  : general
Change #    : 276
Items       : 1
Size        : 116 bytes

$ file image.jpeg 
image.jpeg: ASCII text, with no line terminators

$ open image.jpeg
- see screenshot error

I also tested it with image.png (as my screenshot tool creates pngs), same error on open.

edit: As I said, when drag'n drop it in neovim it works!

[hakonharnes]

Thanks for providing the output of the commands.

Which screenshot tool are you using?

It doesn't work because it's copying the file URL instead of the actual image contents. Following file URLs and reading the contents is a feature planned for 0.2.0. This will also solve #122. pngpaste image.png also produces an incorrect image in this case (it uses the image thumbnail).

Please try these scenarios:

1. Copy an image with the built in screenshot tool using cmd + shift 4. Check if pbctl paste -o image.jpeg works.
2. Go to a web page with an image, right click and select "copy image". Check if pbctl paste -o image.jpeg works.

These scenarios should also work within Neovim.

[codingluke]

Ok i tested it now with the built in screenshot tool and it worked. I am using https://cleanshot.com/ which worked for me with pngpaste. What is still interesting is, that it works when I drag n drop it. See the recording of the cleanshotx screenshot drag n drop 😅

Screen.Recording.2025-05-21.at.08.08.58.mov

[hakonharnes]

I am using https://cleanshot.com/ which worked for me with pngpaste.

Yep, I just confirmed it's working with pngpaste. I'll ping you when pbctl 0.2.0 is released. That should resolve the issue for good :) You can switch the branch back to main for now so you have a working setup.

What is still interesting is, that it works when I drag n drop it.

It works with drag and drop because it's just doing cp screenshot.png test.png under the hood. Neither pngpaste nor pbctl is involved in this case.