In Virtual CRASH 3 or 4, users can import aerial photographs and scale diagrams in nearly any image format, including .tif (or .tiff) format. You can find more information on importing and scaling images in Chapter 9 of the User’s Guide. When importing images from any source, remember Virtual CRASH assumes a single pixel is 1 cm x 1 cm in physical size, so in most cases, the Virtual CRASH scale tool is needed to set the scale between two reference points that are visible in the photo or diagram.