A method of projecting an image with improved safety, using a projection device which comprises a MEMS mirror which oscillates about one or more oscillation axes to scan light from one or more lasers, across a display screen, to project pixels which define an image onto a display screen, the method comprising the steps of, (a) selecting a laser class for the projection device; (b) calculating relationship between maximum accessible emission limit and distance, for the selected laser class, for a predetermined number of black pixels in an image; (c) repeating step (b) a plurality of times, each for a different predetermined number of black pixels in the image, so as to provide a plurality of relationships between maximum accessible emission limit and distance, for the selected laser class, wherein each relationship is for different predetermined number of black pixels in the image; (d) determining the distance between a display screen and the projection device; (e) selecting a desired maximum accessible emission limit for an image which is to be projected by the projection device onto said display screen; (f) selecting a relationship, from the plurality of relationships between maximum accessible emission limit and distance, which contains a maximum accessible emission limit which is equal to the desired maximum accessible emission limit selected in step (e), at the distance determined in step (d) and; (g) identifying the predetermined number of black pixels in the image for that selected relationship; (h) modifying a pixel stream which defines said image which is to be projected by the projection device, so that the pixel stream is provided with said predetermined number of black pixels identified in step (g); (i) receiving each of the black pixels which are provided in the pixel stream, at the MEMS mirror in the projection device, as the MEMS mirror is changing its direction of oscillation about each of the one or more oscillation axes, so that the black pixels appear on opposite sides (32a, b) or around the perimeter (37a,b; 32a,b; 33a,b) of the image when projected on the display screen. (a) selecting a laser class for the projection device; (b) calculating relationship between maximum accessible emission limit and distance, for the selected laser class, for a predetermined number of black pixels in an image; (c) repeating step (b) a plurality of times, each for a different predetermined number of black pixels in the image, so as to provide a plurality of relationships between maximum accessible emission limit and distance, for the selected laser class, wherein each relationship is for different predetermined number of black pixels in the image; (d) determining the distance between a display screen and the projection device; (e) selecting a desired maximum accessible emission limit for an image which is to be projected by the projection device onto said display screen; (f) selecting a relationship, from the plurality of relationships between maximum accessible emission limit and distance, which contains a maximum accessible emission limit which is equal to the desired maximum accessible emission limit selected in step (e), at the distance determined in step (d) and; (g) identifying the predetermined number of black pixels in the image for that selected relationship; (h) modifying a pixel stream which defines said image which is to be projected by the projection device, so that the pixel stream is provided with said predetermined number of black pixels identified in step (g); (i) receiving each of the black pixels which are provided in the pixel stream, at the MEMS mirror in the projection device, as the MEMS mirror is changing its direction of oscillation about each of the one or more oscillation axes, so that the black pixels appear on opposite sides (32a, b) or around the perimeter (37a,b; 32a,b; 33a,b) of the image when projected on the display screen.