I've created a grid and points in QGIS which I used to survey. Using a test image at the moment and I'm trying to fit this image as an overlay within a boundary. When I insert the image it has a white background which I can't remove in QGIS.
Image 1 is what the area looks like, I want to get the survey results inside the red line. Image 2 is what happens when I insert the image, the inserted image of the geophysical results is a .BMP file, the same happens with .TIFF files.
The image is moved into place by georeferencing corners of the boundary area or points on the grid.
If the file is a tif, you can add transparency to it, either by
adding a transparency channel, or
with additional NODATA values.
For the first solution, you might clip your data by a polygon layer of the red line.
For the second solution, you can use the information tool on the raster layer, note the raster value in the black and white areas you want to remove, and add those as NODATA in the layers transparency tab. This might affect data inside your area of interest too, in which case solution 1 is necessary.