1. Create a mark which 256x256px size via marquee tool and cut your floor texture from court.
2. Create a new file in 256x256px size and past your floor, save it as a bmp.
3. Open your floor file. Select Filter->Nvidia Normal Map Filter and click ok, you'll receive purple map:
4. Create a new file in 256x256px size and fill it with black color (R:27 G:27 B: 27). Copy it.
5. Back to your floor file, move to channels section and then past your rectangle onto Blue Channel (Niebieski in a screenshot):
6. Save file as a bmp, and voilla, your bump is ready to use.