I am quite new to QGIS and need some help with this.
Basically I have the coordinates of a piece of land which I can find both through Google Earth and my country's mapping service website. I downloaded a .ECW file with an (raster) orthophotomap from the grid of rectangles of the country where the property is located. After this, I load this orthophoto as a raster layer and try to extract the piece of the map/aerial photo that actually contains the property by using Raster->Extract->Clipper. The result I get here though is not a clipped portion of the original map because QGIS issues an error message which I do not understand why nor what to do about (see attached image), so I can't do the following step to extract the actual contours.
The coordinates that are used are directly input from the image in QGIS by dragging the cursor on the picture, so do not understand why the message about a negative width or hight. Can anyone help?