1)A data is an integer from 0 to 255; 2) Double precision type, with the value range of 0- 1.0.

The saved image is blank, which means that A should be an integer, but it is actually a double type. If the value exceeds the specified value 1.0, it will be displayed in white.

In fact, uint8 () is to convert double into integer data of 0-255, uint8 (unsigned integer, maximum eight bits).

Or you can put one

=

A/255, zoom A to the range of 0- 1.0, and then imwrite(A, filemane), the effect is the same.