How do you change the canvas size in GIMP?

There are two primary ways to change the canvas size in GIMP: increasing it by resizing the canvas and decreasing it by cropping.

Increasing Canvas Size

1. Access the Canvas Size Dialog: Go to Image > Canvas Size. This will open a dialog box that allows you to adjust the canvas dimensions.

2. Adjust Width and Height: You'll see fields for Width and Height.

   • Proportional Resizing: If you want to maintain the aspect ratio of your current image, ensure the chain icon between the Width and Height fields is linked (appears as a connected chain). This means that changing one value will automatically update the other proportionally. If the chain is broken (appears as a broken chain), you can change width and height independently, potentially distorting your image.

   • Enter New Dimensions: Enter the desired Width and/or Height values. If the chain is linked, entering a new value for one dimension will automatically calculate the corresponding value for the other. If the chain is broken, set each value as required.

3. Offset (Positioning): The Offset section controls where the existing image content will be positioned within the newly resized canvas. By default, it's usually centered. You can adjust the X and Y offsets to reposition the image if desired. A negative offset will move the image in that direction.

4. Layer Fill Type: If you are increasing the canvas size, you will expose new areas of the canvas. This setting determines what fills those newly exposed areas. You can choose from various options, such as:

   • Foreground color
   • Background color
   • White
   • Transparency
   • Pattern

5. Resize: Click the "Resize" button. GIMP will then resize the canvas according to your specified dimensions and offset, filling the new areas as indicated.

Decreasing Canvas Size (Cropping)

1. Select the Crop Tool: In the Toolbox, select the Crop Tool (usually looks like a scalpel blade, or rectangle with corner "handles").

2. Define the Crop Area: Click and drag on the image to define the area you want to keep. A selection rectangle will appear. You can adjust the size and position of this rectangle by clicking and dragging its edges or corners.

3. Commit the Crop: Once you're satisfied with the selection, either press the Enter key or double-click inside the selection. GIMP will crop the image to the selected area, effectively reducing the canvas size.