Why do raster values appear in display but not in attribute table?

Question

I received a raster dataset from a colleague consisting of integer values between 1 to 4. The raster displays the correct range of values, but the attribute value contains only a count for values of '0', and no information about the other values that I know are also present based on the display.

This is a problem because I need to perform a series of manipulations and analysis on this data, but these have proved impossible because of this disconnect between how the data is displayed and how it is recorded in the table.

The following images hopefully show clearly the issue I am encountering. The display issues are not my main problem, but seem to symptoms of something happening with this file that I do not understand.

Symbology:

Attribute table:

Display at large spatial scale:

Display after zooming in:

Answer 1

If the attribute's value is floating points then it will not show up in the Attribute table, only integer values are shown. The raster can be converted to int but will result in data loss. In your case there would only be 4 values (1-4).