From my understanding, your 3D array (10x240x132) is in face a 10 page 2D array (240x132). The dimensions of the 3D array are row, column, and page. So each page (3rd dimension of your array) includes one second of data in a 2D array (240x132).
Is there a specific way you are wanting to display the frame grayscale data? Do you want to see 10 separate 2D array's, each containing one second worth of data (240x132)?