Image Processing Reference
3.11 Using the Paths Tool as a Masking
Tool—Using Filters for Light Effects
The Paths tool has multiple uses: On the one hand, it enables you to produce
free (vector-based) shapes that can be transformed, filled, and otherwise
edited. On the other hand, GIMP supports a variety of methods to create
selections from paths and transform selections into paths—for example, in
the Paths dialog or in the Select menu.
Paths are not limited to straight-line objects and edges. On the contrary,
they are extremely useful when creating and tracing complex objects and
shapes. Paths can be aligned to the contours of even very complicated image
objects with great precision. They can be used to extract regularly shaped,
curved objects: glasses, cars, etc.
In the next exercise, you will use paths to copy a wine glass (a somewhat
regularly curved object) from an image, which is a more difficult task with
other Select tools.
3.11.1 Copying a Wine Glass and Creating a
Drop Shadow—Overview of the Steps Involved
Follow these steps to copy a wine glass and create a drop shadow:
• Open the wineglass.png image from the SampleImages folder.
• Select the Paths tool to create a path, following the contours of the wine
• Create a selection from the path; add 3 px of feathering to the selection.
• Select the Edit > Copy menu item to copy the wine glass. Choose Edit >
Paste and insert as a new layer in the image. Remember to name the layer.
• Save the image (without combining the layers) as wineglass2.xcf .
• Copy the path and transform it so that the wine glass casts a perspective
• From the shadow path, create a selection with a strong, soft border, and
then fill the border with the color black on the shadow layer.
• On the background layer, create a linear gradient blend from pale pink to
burgundy red (from top to bottom).
• Reduce the opacity of the layer with the pasted wine glass to about 90%.
Alternatively, you can use a large eraser with 10% opacity to erase some
color from the wine glass. Whichever method you choose will serve to
increase the transparency of the glass.
• Use the Light and Shadow > Lens Flare filter to create two highlights spots:
one at the upper rim of the glass and another at the base of the glass.
• Save your image.