Creating button images

• Open your scanned image with gimp: gimp FILENAME
• Add an Alpha Channel to the layer: Layer -> Transparency -> Add Alpha Channel
• Choose the Ellipse Select tool and set a Fixed: Aspect Ratio of 1:1
• Select the largest circular section that you can from the scanned image, cropping any outline within the image
• Crop the layer to selection: Layer -> Crop to Selection
• Scale the selection to 145x145 to allow space for the shadow: Layer -> Scale Layer -> 145 -> Scale
• Zoom the image to 400%: View -> Zoom -> 400%
• Import the shadow as a layer: File -> Open as layers -> shadow.png (file found in https://gist.github.com/alwayslurking/c8da68a0faec7e33b2c0 )
• Open the Layers dialogue: Windows -> Dockable Dialogues -> Layers
• Make sure the imported layer is on top and selected
• Choose the Move tool and set it to Move the active layer
• Align the shadow with the button
• Move the shadow layer down the stack using the Layer dialogue
• Select the button layer and merge it down: Layer -> Merge Down
• Crop the image size to the new layer: Image -> Fit Canvas to Layers
• If necessary, rescale that image to 150x150: Image -> Scale Image
• Export the edited image with a new filename: File -> Export