A label modification unit may receive a label modification input associated with an image. The label modification unit may process, using an image filtering, the label modification input to convert the image to a bitmap for raster printing the image via a laser printhead. The label modification unit may determine, based on the bitmap, an array of power factors for a light beam that is configured to be emitted by a laser of the laser printhead and raster print the image. The label modification unit may control the laser of the laser printhead in association with raster printing the image on a rewriteable label according to the array of power factors.