Abstract: A method for detecting a keystroke operated on a projected keyboard, and an associated device are disclosed. A first image and a second image of the projected keyboard are captured. Preferably, while the first image is taken, an infrared (IR) beam is projected on the keyboard, and while the second image is taken, the IR beam is switched off. The second image is subtracted from the first image to remove noise and detect a difference between the first and second image. The location where the difference is detected is associated with the keystroke. The location of the keystroke is determined in relation to the projected image of the keyboard. The location is then associated with a key of the keyboard based on a keyboard layout stored in a memory. A command signal corresponding to the key is then generated for transmittal to the computing device.