Captain 3D presents
Part Two - Photoshop
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Open your left and right images in Photoshop. We are now going to blend the stereo information by using Photoshop's RGB channels. I have my preferences set to show Channels in colour to make things clearer.
In this example, I am going to leave the images in RGB colour. This is only possible because there are no strong red or blue shades in my scene which would otherwise conflict with the specs when viewed for 3D. You can check if your images are suitable for colour anaglyph by viewing your rendering through some 3D specs first. If you see any disturbing colour clashes then you can either reduce the saturation of those shades or in very difficult cases, just switch to Grayscale then back to RGB to neutralise all colours. |
| With the left image active, click on its red channel, select all and copy. You can now close this file. Now with the right image active, click on its red channel and paste. You will notice the image appear to shift. That is because we have swapped the viewpoints. This file now has all left information in the red channel and all right information in green and blue which together make cyan. |
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To see what effect this has on the image, click on the eye symbol of the RGB channel being careful not actually select the channel. Now you can see that familiar anaglyph style picture. But before it is finished the channels must be carefully aligned for the clearest stereo effect. At this point the whole scene appears to be coming forward from the screen and there is quite a lot of ghosting - yuk. |
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The red/left channel must be nudged over to the left to align with the blue/green channels. This will also have the effect of dropping the scene back through the frame as if you are looking in through a window. Wherever the two images align perfectly, will be the point that appears to be on the same plane as the monitors surface. In this image everything should fall slightly behind the screen in order to look natural. It is best to adjust the channels position while wearing red/cyan specs. Run your mouse over the next three images while wearing specs to help see how it drops back. The cursor is only in front of the chair in the final, correct image. |
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Now you can see why the extra space at the sides was needed. Now crop your image to tidy it up.
Well designed stereo cameras have this cropping built in by offsetting the lenses slightly left and right from the exposed film frame. If you are going to save your finished image as a JPEG for the web, be careful with the amount of compression you choose as this adds noise to the colours adding to the problem of ghosting. You can see over 200 digital and photographic anaglyphs in my Stereo Gallery. Let know where I can see your Stereo Renderings - e-mail |