Fuzzy selection (also called 'magic wand') is a tool for selecting areas of image (or layer) with the same/similar colour. It is very important to pick the starting point correctly, or either you will get something completely different from what you want (well, not always, but usually yes). Wand is a good choice for selecting objects with sharp edges. It is also great for touching up selections, or selecting areas within some contour.
- Modes - determines the way of creating the selection, whether it'll be combined with existing one and such
- Antialiasing - causes the boundary of the selection to be drawn smoother
- Feather edge - causes the boundary of the selection to be blurred
- Select transparent areas - gives the ability to select areas completely transparent
- Sample merged - creates a selection from actual image, instead from the active layer
- Threshold - determines the range of colours
- Select by - select, which component shall be used for calculating the similarity
Modes, Antialiasing and Feather Edges
Select transparent areas
After selecting this option, the Free Selection tool will have the ability to select completely transparent areas. If this option is unchecked, transparent areas will never be selected.
This option has any meaning when you have several layers on the image, and the active layer is either semi-transparent or set to another mode than Normal. If it is so, the colours present in the layer, will be different from the ones in the real image.
This slider determines the range of colours that will be selected at the moment of creation of the selection. Higher threshold - larger resolution. Note that with higher selection also bigger gaps are possible to be between the selections. After the first button-press (but before releasing it), dragging the pointer downward (or to the right) will increase the size of the selection, while dragging upward (or to the left) will decrease the size of it. Thus the first settings of threshold do not really matter, as you can modify them any time afterwards.
This option will change the component that The GIMP will use for calculating the selection. The possible components are: Composite. Red, Green, Blue, Hue, Saturation and Value.