The researchers studied how the size of grains in satellite images affects the patterns of urban forests in Shenyang. They looked at 25 different landscape indices and found that some indices changed consistently with grain size, while others showed different patterns. They also discovered that certain types of urban forests were more sensitive to changes in patch number, while others were more affected by patch size. Ultimately, they determined that a grain size of 5 meters was the best for studying urban forest patterns in Shenyang.