Using Raster clipper in QGIS?

Question

I have several raster tiles . I have merged them. I don't know why I get a black boarder around the merged map (the pixel values are 0) I have created a polygon for the area of interest to remove the black area but the raster clipper seems doesn't work and again after the clip, I have the black border around my raster. First I don't know why Qgis creates the black border and

Second I don't know why the Raster clipper doesn't work!

I now that I can remove the black border (Just for visualization purposes) through property --> transparency tab. I am looking for a permanent solution)

Answer 1

If the raster image and polygon layer have the same projection the clip should work properly. To remove the black border in No Data value, you can assign -9999 in No Data value as you can see below:

Select Mask layer to select the polygon cutline that you want to use as clip layer, and select Crop the extent of the target dataset to the extent of the cutline