A camera unit includes a display for displaying an image to be captured; an image sensor for digitally capturing the displayed image; a card reader having a linear scanner for scanning a surface of a removable card to sense a plurality of dots printed on the surface of the removable card, the plurality of dots representing a bit pattern encoding a program script; a card interface for receiving a signal from the card reader indicative of the sensed plurality of dots printed on the surface of the card, and decoding the sensed plurality of dots into the program script; and a printer configured to print a distorted image on print media, the distorted image being a version of the captured image distorted in accordance with the program script. The card reader comprises a moulding housing therewithin a plurality of light sources, the moulding being transparent to light from the light sources and shaped to focus the light on the removable card.