color to B&W

[unleash]

I wanted to make some bump maps out of reall photographs....
Bump maps are textures that define the height(texture) in an object....so you must make a bump map if you want something to look realistic....

Now i got an detailed photograp of an concrete wall, and i must give the difference in heigt in that picture....black is heigh, white is flat. So i must change this photo to an B&W image but how?

[Tamlin]

There are lots of ways to convert colour images to black & white. For most of my photos, where I want to have maximum control over tone and contrast, I usually use one or more Channel Mixer adjustment layers, along with a Levels and/or Curves adjustment layer. This might be a bit involved for a bump map, though. The easiest option is to desaturate the colour image (Image > Adjustments > Desaturate) although this tends to leave you with a black & white image that lacks the sort of contrast you need for a good bump map. A better way would be to look in the Channels palette and compare the Red, Green and Blue channels (if your image is RGB). Pick the channel with the best contrast, then right-click it and select Duplicate Channel. Save it as a New document. This will create a new B&W image based on the channel you selected, which you can then use for your bump-map.

[unleash]

Yep, i tried what you said tamlin and it was very close....
But it's not that i should covert images 1on1 in b&w,
It's more that i must make surtain spots black other white and the rest somesort of grey.....so the proggram sees the differtent and translates it into depth. With an normal color image the programm get's a strange "view" on the difference...

I will post a link here when I got the general idea.....then maybe someone can help me a bit further

[Uniko]

I'm familiar with the bump map concept (I'm a 3DS guy).
You don't want black and white you want grayscale.
To manipulate height, the 3D prog must have some sort of degree from white to black. Problems arrise if you don't like what the 3d program is doing, so you must do it yourself, as tamlin said, desaturate the image, add a new layer and call it "white" (or down) paint in this layer with white at different softness and opacities where you want the height to became flat. Do the same with a new layer called "black" (or up).
Do some experiments with this setup and you'll get what you want.

Good luck

[unleash]

Thanks, and about the prog.......im getting seriosly irritaded by it...but now it's it will wor ki hope

Thanks Tamlin and Uniko will try what you said

[ovidiua2003]

You could Play with the levels (Ctrl + L) of the image after you desaturate it. It will give a much better result regarding the contrast and greyish area you need. I use this technique to make bump maps for 3dsmax. Hope it helps

[seleneyue]

I would desaturate by hand (using the desaturate brush tool) if you wanted a lot of detail. you usually don't need that much, tho for things like skin imperfections you want it to be perfect. this method is slow, but you can tweak it easier, imo.
which is the default level for your bump-map? whether it's white (rarely), grey, or black can affect how you make your bump-map. if it's black, increase the overall darkness but use small history brush to go back to really white places (or forget it and just up the bump strength.. lol), but if you prefer the default grey, then play with the curves until the middle heights are pretty much greyed out, then go into levels and make sure it's the right shade of grey.

[agentxi]

hey unleashed could you post up the image you are trying to make into a bump map?

personally i hate using a photo for textures, but if you do, you should get rid of all lighting out of the image, the reason being is that you do not want permanent lighting and shadows in your textures...cuz once you bring your textures into (umm maya? i think i've seen you say)... the 3d program will handle all the lighting and shadowing for you.

so once your source image has no lighting or shadows in it, then you can take the file, take all the color value's out, and then work with level's (curves work great but takes a bit to get used to them). The level's will help bring out the value's for you. and don't be afraid to use textured brushes on new layers and paint in your own to help blend in the effect that you want.

With the new layers I would turn the opacity down pretty low, you'll want your effects to be subtle.

also one last thing using a gaussian blur help's create the a softer bump map, but i wouldn't blur your main working file, i would do it on the exported image, that way you can go back and tweak as needed at a later date.