Some settings in the Symbology tab require that a histogram is built (e.g., using the Classified renderer, or using a histogram stretch). If a histogram is not present, ArcMap prompts the user to compute the histogram.If a histogram is computed, that histogram is not persisted in the raster dataset; it is only persisted for that particular ArcMap session. The next time the same raster dataset is used in a new ArcMap session, the histogram must be computed again.
This is caused by a bug that affects the histograms for the IMG and TIFF formats in ArcGIS 9.3.
Get help from ArcGIS experts
Download the Esri Support App