How to Curve an Object in GIMP

Learning to curve objects in GIMP, a free image-manipulation program, will enable you to create images that might be difficult to create using GIMP's standard tools. For example, creating the smooth parabolic arc of a stream of water would likely take significant trial and error with the Paintbrush tool; but using one of GIMP's distortion filters can produce the arc with a few mouse clicks. Filters are software functions that change or create images by applying geometric calculations. Many filters produce imagery that closely resembles the appearance of phenomena in the physical world, such as lens flares and shadows.

Instructions

1. Click the "Open" command on the File menu. Navigate to an image file containing a object that you'd like to curve with GIMP and double-click on the file. The image will be opened for modification.

2. Click the "Tool Palette" icon, which is shaped like a lasso, to run the Free Selection tool. You use this tool to define selection regions of any shape.

3. Drag your mouse cursor around the object you want to bend, then release the mouse to make GIMP select the object. GIMP will indicate the object's selected state by displaying a moving dashed line around the object.

4. Click the "Filter" menu and then click the "Distort" sub-menu to display a list of commands you can use to distort an existing image, as opposed to creating a new image. Click the "Curve bend" item, which launches a command for interactively curving a selection region. GIMP will display a dialog box with controls you can use to curve the selection.

5. Click the middle of the horizontal line that appears in the grid in the "Curve bend" dialog box. This line represents the top horizontal edge of your selection region. Clicking the line places a new point on the line. GIMP will pass a smooth curve through this point no matter where you move it.

6. Drag the point you just created upward to make the selection's top edge bow up. Click the "Mirror" button in the dialog box to duplicate the curved upper edge to the bottom edge of the selection. As the top and bottom edge of the selection region surrounding your object are now curved, the object itself is now curved.

7. Click "OK" to close the dialog box and commit to the curve transformation.

References

• "The GIMP User Manual"; GIMP Documentation Team; 2009