Spatial processes are widely used in data analysis, specifically image processing. In image processing, examining periodic images is one of the most critical challenges. To investigate this issue, we can use periodically correlated spatial processes. To this end, it is necessary to determine whether the images are periodic or not, and if they are, what type of period it is. In the current study, we first introduce and express the properties of periodically correlated spatial processes. Then, we present a spatial periodogram to determine the period of periodically correlated spatial processes. Finally, we will elaborate on its usage to recognize the periodicity of the images.