Based on the resolution of the original image and the generated image pyramid, the program specifies the starting level (initial value) and ending level (terminal value) for tile hierarchy as Level 1 to Level 3.

According to the defined hierarchy range, three hierarchical folders are created under the tile root directory. These folders are named with their corresponding hierarchy level numbers. Therefore, the three folders are named 1, 2, and 3 respectively. As shown below, this establishes the second-level directory structure of the tile catalog.