Order of disabling the background color for raster mosaics

1.        Import the source TIFF files into GIS. In the import dialog disable compression of the output raster:

2.        We control the lack of compression in the raster parameters:

3.        Apply the «Transparent color» mode to all document rasters:

4.        In the «Transparent color» dialog, select the «Transparent color» option and click on the «...» button:

5.        In the «Color» dialog, click on the «Define color» button:

6.        In the «Color» dialog we set the RGB components of the raster background color:

For the rasters from the above example, the background color corresponds to black (0, 0, 0).

7.        The result of disabling the background color for all document rasters: