Above, The Photoshop lighting effects dialogue. Note the Texture Channel drop-down needs to be set to red, blue or green for the bump effect to work.

Above and below, Corel Photo-Paint lighting effects dialogue. Note the general settings, which can be adjusted to achieve the best effect.

Corel Photo-Paint: Effects/Render/Lighting Effects

Photoshop: Filter/Render/Lighting Effects

  A bump map is an image were the tonal values represent the height and depth of the texture. Like a contour map, the lighter the tone, the higher from the floor. The filter sees the image in this way and applies the lighting and highlights as if it were 3D (clever little thing!). Bump maps are used mainly in 3D rendering to give the surface of the object a texture that changes with any local animated lighting conditions.
  Both Photoshop and Photo-Paint have similar dialogue boxes. Studying the pictures here will show the general settings for achieving a bump. The depth of the bump depends on the tonal difference of the image and the 'Height:Flat-Mountainous' slider (Photoshop) or 'Relief' slider (Photo-Paint) on each dialogue box. The lighting direction can be set by movable handles which appear in the preview window.

A greyscale bump map.

'Bumped' image

'Bumped' with colour light

A brick bump map

'Bumped'  image

Two colour bump (PS)

Two colour bump (PP)

Above, Photoshop's  dialogue settings for a two colour bump

Above and below, The Photo-Paint basic settings for two colour bump.  

 Producing a two colour bump with lighting from two different directions is the same as a single colour bump. Extra lights can be added either by clicking the + button in Photo-Paint or dragging the light bulb symbol into the preview window in Photoshop. After choosing the colour of each light a fair bit of fiddling may be necessary- lighting angles, brightness etc.

 Your settings can be saved for future use in the preset 'Style' drop-down.

 If you wish to try this out for yourself there are a small number of tiled bump maps in my free texture section.

 IMPORTANT NOTE: Generaly bump mapping images only work properly on 24 bit RGB colour images.

More bump map effects using spot lights