A three dimensional imaging system includes a first laser emitting light at a first wavelength, and a scanner for scanning the laser light in a pattern on the target area. A photo detector receives light reflected from the target area as a contrasted vein image, resulting from differential absorption and reflection therein of the first wavelength of light. The intensity of the first laser is incrementally increased, and the photo detector thereby receives a plurality of contrasted vein images, each being at incrementally distinct depths beneath the target skin surface. Image processing is performed on the plurality of vein images to successively layer the veins in the images according to their depth, to create a single processed vein image. A second laser emitting a second wavelength of light is used in combination with the scanner to project the processed vein image onto the target area to overlay the veins therein.