A method for a compressive sampling to capture an image of the object by using a spatial light modulator and a photo-detector, the method includes driving the spatial light modulator in a first rough sampling mode which is executed by using first coded patterns; detecting signals from the photo-detector to obtain a first data at t=t1; detecting signals from the photo-detector to obtain a second data at t=t2, where t2>t1; and changing the first rough sampling mode to a second rough sampling mode which is executed by using second coded patterns finer than the first coded patterns when a difference between the first data and the second data is greater than a threshold value.