Transparency in TGA images

[es157]

Hi.

I've long ago learned that most modders use and reccomend GIMP as the best tool to edit images, specially when creating transparent areas is needed. However, it often frustrates me how this tool tends to mess up with any image that is minimally complex.

For instance, I am only allowed to turn either white or black-coloured areas into transparent. Okay there. However, the program also picks several light-coloured-but-not-white (or dark-but-not-black) and makes them transparent too, despite me giving clear instructions to only make the white (or black) transparent.

And what is oddest, the program sometimes changes the colour of certain areas, for example, turning light brown into golden.

I've searched many places that discuss TW, and basically all of them simply suggest using GIMP and give instructions on how to do it. But it is exactly by following those instructions that I found my problem. I wonder, why does GIMP change the colour of stuff, and how can I make sure that it only turns transparent the exact colour shade that I choose?

[Gigantus]

Use 'colors\color to alpha' and then play with the variables - the preview will show you what you will get. The 'opacity threshold' will restrict the 'spread' of the effect with regards to nearest RGB values. The 'mode' will change the method of application. Hovering over the select tool icon will give you a descriptive text.
Once you have the desired setting simply save it as 'preset' with a descriptive name by clicking the plus sign on the right.

[es157]

Use 'colors\color to alpha' and then play with the variables - the preview will show you what you will get. The 'opacity threshold' will restrict the 'spread' of the effect with regards to nearest RGB values. The 'mode' will change the method of application. Hovering over the select tool icon will give you a descriptive text.
Once you have the desired setting simply save it as 'preset' with a descriptive name by clicking the plus sign on the right.

So the trick is using the opacity bar to adjust the results? Thanks for the clarification. I'll do some testing with it and report if I continue to find issues.

Perhaps I should clearify that I'm using 0,000 as the value for transparency threshold and 1,000 as the value for opacity. Those are the standard values. I haven't touched them. I assume that those are the most shade-precise settings?

Here is the image I'm trying to edit right now:


As this is a building portrait, I mean to remove those white borders and nothing else. But when I try, the GIMP also removes the sky and changes the colour of the rest of the structure.

As a side note, I also noticed that vanilla building portraits have a sort of "shadow" outside the margins. I have no idea how to emulate that in my own portraits...

[Gigantus]

Outside edge - simply use the rectangle select, invert the selection and delete. Most of the times you will end up with transparency. Selecting with the magic wand (fuzzy select mode to avoid selecting elsewhere) and then changing the alpha value does the trick as well.

The shadow is done with a lighting setting - filters\light and shadow\drop shadow is my favorite. Best to make a template of the frame only and then simply insert pics - you'll be amazed how well that works, check out the RotK templates. To get the pic under the shadow you will need to open the pic as layer and then position that layer under the frame layer.

[es157]

Outside edge - simply use the rectangle select, invert the selection and delete. Most of the times you will end up with transparency. Selecting with the magic wand (fuzzy select mode to avoid selecting elsewhere) and then changing the alpha value does the trick as well.

The shadow is done with a lighting setting - filters\light and shadow\drop shadow is my favorite. Best to make a template of the frame only and then simply insert pics - you'll be amazed how well that works, check out the RotK templates. To get the pic under the shadow you will need to open the pic as layer and then position that layer under the frame layer.

I'm confused by most of those terms. In fact I'm not that familiar with GIMP and its over-complex mechanics, but I'll try it out and see if I can catch the trick. Thanks.