It is much easier to start with a photo that has light seams and dark bricks. You can always adjust the colors later, but making a Normal map for the Bump is much easier with a high contrast combo like this.
By doing some level, saturation, and manual painting adjustments, the resulting height map looks like this:
Below are the rest of the maps we used. The seams are usually rougher and less reflective, so they are darker in the maps.
The Normal map strength can be adjusted in the range 1~6 to change how much the bricks are sticking out.
