The Pixel Value indicator displays information about the pixel underlying the pointer or about a sampled pixel or region of pixels. (You can sample a single pixel from the Viewer by pressing Ctrl/Cmd while clicking, a region from the Viewer by pressing Ctrl/Cmd+Shift while dragging, a single pixel from the node’s input by pressing Ctrl/Cmd+Alt while clicking, and a region from the node’s input by pressing Ctrl/Cmd+Alt+Shift while dragging.) From left to right, the indicator displays the following about the current pixel or sample: its x and y position; its Red, Green, Blue, and Alpha values; and other values depending on the color type you have selected from the color type menu on the right.
The Format indicator displays the image resolution and the size of the bounding box.