Enjoy this free tutorial for turning this normal image into a beautiful, colour infrared effect in Photoshop
Before/After
Download the start image from www.sxc.hu, taken by Tomislav Alajbeg.
Open this image from the link above. Duplicate the Background layer by heading to Layer>Duplicate, or hit Cmd/Ctrl+J for the shortcut. Change its blend mode to Overlay from the options in the Layers palette. Also, lower its Opacity to 60% to reduce the strength.
To turn the image to black and white with an infrared style, go to Layer>New Adjustment Layer>Channel Mixer. This applies a new adjustment to the top of your layer stack and can be edited at any time. Tick the Monochrome option in the adjustment to kick things off.
The Channel Mixer adjustment divides the image into three RGB adjustments. To turn the image infrared, slide the Red adjustment to +100. Notice how the sky and the water in the image turn brighter as a result of changing this.
Boost the Green channel to its maximum possible value of +200. This will turn most of the image to a bleached white, but not to worry! The final adjustment is to move the Blue channel down to -200 to bring the image back to a high-contrast monochrome.
Close down the Channel Mixer adjustment and head to the Layers palette. Drag the Channel Mixer layer down the stack so that it’s sitting between the Background layer and the duplicate image. Lower its Opacity to 90% to reduce the contrast slightly.
Make sure the duplicated Background (top layer) is selected before continuing. To alter the colour values of that layer, go to Image>Adjustments>Hue/Saturation. Select Yellow from the list of colours (default to Master). This particular adjustment should be altered through the Image menu and not as an adjustment layer.
With Yellow chosen, only the trees will be affected. Move the Hue slider to -130 and the Saturation to +40. This will change the trees to a vivid purple, but they could be any other colour of your choosing. Hit OK to apply the new tint to the image.
To re-create the soft look of an infrared image, go to Filter>Blur>Gaussian Blur. Enter 10px for the Radius and hit OK. You can go back into the Filter menu and choose the option at the very top to reapply the filter for another dose of blurring if needed.
Add a new blank layer by clicking once on the Create New Layer button. To fill this layer with white, go to Edit>Fill and under Contents select White. Hit OK and then change its blend mode to Multiply in the Layers palette.
With the white layer selected, go to Filter>Texture>Grain. Firstly, set the Grain Type to Constrasty. Clumped also works well, but it’s down to preference which one you go for. This will give us a traditional film textured look.
Shift the Contrast adjustment up to 100 and hit OK to add the grain effect. At the moment the grain is in colour, so go to Image>Adjustments>Desaturate. Also, lower the Opacity of the layer to 80% to make it less obvious.
To make the overall image lighter, add a Levels adjustment layer (using the black and white icon at the bottom of the Layers palette). Move the middle arrow (midtones) further to the left from a value of 1.00 to 1.30. This will lighten the overall effect to complete the image.