1. A method of operating a multi-beam scanning system forming an image on a two dimensional image plane (214, 500), comprising: illuminating a spatial light modulator including a number of SLM pixels (326, 508) arranged in parallel in a pixels arranged direction along a long axis of the SLM, each SLM pixel having a first pixel pitch; providing drive signals including image data to the SLM pixels to modulate light incident thereon to generate beams of modulated light reflected from the SLM; scanning, in a first scanning direction (x, 514), the beams of modulated light across the 2D imaging plane to form a substantially linear swath using a collimate lens, a scan mirror moved about a first axis, and an imaging lens; and scanning the linear swath across the 2D imaging plane in a second scanning direction (y) orthogonal to a long axis of the linear swath to form a plurality of linear swaths, using the collimate lens, the scan mirror moved about a second axis, and the imaging lens, wherein the method compensates for distortion along the long axis of the linear swaths caused by the imaging lens for beams off the optical axis of the imaging lens by providing a controlled pitch which is smaller than a required resolution for forming the image, in both the pixels arranged direction by providing said first pixel pitch to be smaller than the required resolution, and in the first scanning direction on the image plane, to provide an address grid of individually addressable address pixels having said controlled pitch, and by providing compensated image data to said address pixels as said drive signals including image data, and wherein address pixels in neighboring linear swaths scanned onto the 2D imaging plane overlap. illuminating a spatial light modulator including a number of SLM pixels (326, 508) arranged in parallel in a pixels arranged direction along a long axis of the SLM, each SLM pixel having a first pixel pitch; providing drive signals including image data to the SLM pixels to modulate light incident thereon to generate beams of modulated light reflected from the SLM; scanning, in a first scanning direction (x, 514), the beams of modulated light across the 2D imaging plane to form a substantially linear swath using a collimate lens, a scan mirror moved about a first axis, and an imaging lens; and scanning the linear swath across the 2D imaging plane in a second scanning direction (y) orthogonal to a long axis of the linear swath to form a plurality of linear swaths, using the collimate lens, the scan mirror moved about a second axis, and the imaging lens, wherein the method compensates for distortion along the long axis of the linear swaths caused by the imaging lens for beams off the optical axis of the imaging lens by providing a controlled pitch which is smaller than a required resolution for forming the image, in both the pixels arranged direction by providing said first pixel pitch to be smaller than the required resolution, and in the first scanning direction on the image plane, to provide an address grid of individually addressable address pixels having said controlled pitch, and by providing compensated image data to said address pixels as said drive signals including image data, and wherein address pixels in neighboring linear swaths scanned onto the 2D imaging plane overlap.