44 replies to this topic

[Jotaf]

Updated 9/10/2011:

Right, it turns out that the original plug-in is no longer compatible with PDN. I fixed it, and also decided to make it open-source! This way I can take contributions to improve this, and maybe it will also help improve other plug-ins with this sort of alpha handling.

The code is only a few lines of code long, but it uses (*gasp!*) MATH! Check it out if you're the coder type.

The attached zip file includes both the DLL and source code (which you can open with CodeLab).



Original post:

Hi there! Long time lurker, first time poster. PDN has been my favorite graphics tool for quite some time.

There's the old problem of recovering alpha information lost in compositing, for example when you *ahem* borrow images from the web. Say, smooth edge pixels on a black background; you'd prefer if they were transparent. A few plugins are available, and they do OK 90% of the time, but they fall short in recovering the original color information...

See, it's not enough to figure out the alpha channel. You also have to use it to change the colors so they will look good when compositing again. Otherwise, there would be a visible halo (the color of the background) around the edge. AFAIK this happens with all existing plugins to eliminate backgrounds. So, I decided to make this one.

I've got some pictures to demonstrate the effect and illustrate what I mean about the color correction

Attached Thumbnails

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Attached Files

•  GrimColorReaper.zip   6.05K   10943 downloads

Edited by Jotaf, 11 October 2011 - 04:28 AM.

[yy10]

nice plug in. just downloaded it. the problem is, after you kill the colour, there will be some lines around the edges of the images. you should kill those lines too. like the feather plug in

[yellowman]

I like the idea, how could you choose the color that want to kill it, can you post some more screenshots of the plugin GUI please?

[Simon Brown]

Unofficial UI screenshot:

[Mike Ryan]

Can somebody confirm if this is similar to a Color to Alpha plugin?

[Leif]

I would suggest a slightly deferent name, as there is another plugin with that name. Right now I have two plugins with the same name.

[pyrochild]

You're already using IndirectUI, so why not use the Color Wheel control instead of a dropdown?

[Jotaf]

Thank you yy10 and yellowman, and everyone else for the feedback!

You're already using IndirectUI, so why not use the Color Wheel control instead of a dropdown?

I considered it, but then found that for this application it's a waste of space. Most of the time you'll choose the color with the color picker or use a predefined one like black or white; so why would you need the color wheel to adjust it? It would just be ignored. (IMO; unless you guys argue otherwise...)

I would suggest a slightly deferent name, as there is another plugin with that name. Right now I have two plugins with the same name.

Damn, that's unfortunate. I thought it was original enough. Any suggestions?

nice plug in. just downloaded it. the problem is, after you kill the colour, there will be some lines around the edges of the images. you should kill those lines too. like the feather plug in

Hm, I don't really know what you mean. It's supposed to eliminate those kinds of artifacts. If some transparent colors remain (ie, small patches of very transparent pixels), you can cut them off automatically with the second slider.

Can somebody confirm if this is similar to a Color to Alpha plugin?

It's similar to all those plugins, the main advantage is the color correction that prettifies a lot the pixels with modified alpha. See the screenshot (the "no color correction" shot is what you'd get with other plugins).

[ChronosRegex]

I would suggest a slightly deferent name, as there is another plugin with that name. Right now I have two plugins with the same name.

Damn, that's unfortunate. I thought it was original enough. Any suggestions?

how about Color Murderer?

[Jotaf]

I would suggest a slightly deferent name, as there is another plugin with that name. Right now I have two plugins with the same name.

Damn, that's unfortunate. I thought it was original enough. Any suggestions?

how about Color Murderer?

Good, good. Color Sniper?

("I was thinking about something a bit less blasphemous." -Ned Flanders)

[Jotaf]

Let me just leave you with a couple more pics, I hope it's ok :wink:

Attached Images

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[Ego Eram Reputo]

I would suggest a slightly deferent name, as there is another plugin with that name. Right now I have two plugins with the same name.

Damn, that's unfortunate. I thought it was original enough. Any suggestions?

Check the Plugin Index for the current list of plugins. The index has them listed by name and author.

BTW: a revision is due out this weekend.

Grim Color Reaper ?

[Simon Brown]

Backgroundless?

[Jotaf]

The index has them listed by name and author.

BTW: a revision is due out this weekend.

Grim Color Reaper ?

Hey thanks for the tip! That would be a pimpin' name too, since we're talking about taking that poor color's life.

Backgroundless?

This is a bit more serious so I'll have to consider it too

Feel free to add any more suggestions, I'm afraid I'll be silent for about a week but when I get back I'll change the name to one of those (unless another one pops up in the meanwhile!).

[ken_dot_pistol]

I like this plugin, very nice . could you post the source. please.
thnak you.

[Alph Tech / STUART]

This is basically just chroma key for any color. Why not call it Chroma Key?

"Color to Alpha" was another simple suggestion.

Is "Isolate" taken?

[Ego Eram Reputo]

We already have plugins called "Chroma Key" and "Color to Alpha". Check out the latest revision of the plugin index: viewtopic.php?f=16&t=30570

"Isolate Color" might work as we only have "Isolate Lineart", but does this plugin merely isolate or completely extinguish the color?

[Mike Ryan]

Hmm, the plugin has to do with transparency and specific colors, Decolourize?

[Jotaf]

Thanks for all the suggestions, I went with Grim Color Reaper out of a whim mostly (thanks EER!), and also because I didn't wanna waste the cool icon. Unless most of you think it's too silly or there's an even better name around. Oh and it looks good next to a skull icon

The code is pretty small, you'll be surprised! What's really special are the formulas for correcting the color, although they're not rocket science. Is there a real interest in seeing the code? If there is, I'll post it whenever I get back to a place with net access again (summer vacations are when I get to detox myself from the internet addiction!).

[Jotaf]

does this plugin merely isolate or completely extinguish the color?

The idea is that it completely extinguishes the color, not only through alpha but through color modification also. So I tried to convey that through the naming too