Geographic information is embedded in the TIFF data file in the form of descriptive tags. Translation and rotation are both 0. The last two lines are the UTM values of the upper left pixel of the data set. For example, when displayed using graphics arts software, the DRG is a simple picture on a computer screen. If both files are located in the same directory, the image file will be displayed in UTM units.
Metadata are also important for establishing quality control.
Specific information can be extracted from metadata files and used to georeference the DRG depending on the requirements of individual raster viewing applications. To be consistent with other USGS digital data, the image is cast on the UTM projection. Therefore, the projection of the DRG will not always be consistent with the credit note on the image collar. Because it is fit to the theoretical quadrangle corners based on the UTM projection, the DRG may have distortions outside the map projection lines. Color standardization - Standard DRG's have a maximum of 13 indexed colors.