To do this we will use the Photoshop crop tool. It's not critical to crop the exactly same area in both the IR and visual images, just make sure you get enough of both images to cover the area you want. This is an area where you will have to develop your own techniques and judgement. In general, the visual image will have to be lightened and the IR image will need be darkened. Now that your IR and VIS images are adjusted in gray scale, we will now adjust the color.
Lets start with the visual image.
The image should look yellow. Leave the RED channel at 255. Again, these are only guidelines and later you may want to experiment with these values. A similar procedure is used on the IR image. The image turns cyan.