Blending Two Images with GIMP

Included in this tutorial -

• Resizing a Canvas
• Creating a new transparent layer
• Anchor a floating layer
• Using a layer mask
• Using the gradient tool
• Flattening an image

• Open both pictures you intend to blend

Activate the one you intend to use as the base image

Increase the canvas size of this image to accommodate pasting the overlapping image

• Image - Canvas Size

• Break the Width/Height link by clicking on the chain icon

• If the two images are the same size you need to nearly double the width

Create a new transparent layer

Layer - New Layer ... (or click the new layer icon in the layers dialog)

• Name the new layer 'Overlay layer'

• Select Transparency as Layer Fill Type

Activate the second image which will be the overlay layer and copy it

• Edit - Copy (or Ctrl+C)

Activate the base image and paste the copy of the second image onto it

• Edit - Paste (or Ctrl+V)

Anchor the floating pasted layer to the transparent Overlay layer

• Layer - Anchor Layer (or Ctrl+H, or click the anchor icon in the layers dialog)

Use the Move tool to position the Overlay layer so that it overlaps the base layer as much as you like

• Note that it's helpful to slide the Overlay layer down a little so you can see how much overlap you've got

Add a layer mask to the Overlay layer

• In the layer dialog, right-click the Overlay layer

• Add Layer Mask ...

• Select White (full opacity)

Paint a black-to-white gradient on the layer mask

Select the Gradient tool with the options shown

• Draw a straight line (use Ctrl to constrain your line if necessary) from the left edge of the Overlap layer to the right edge of the base image

• The two images should now be blended together as shown

Even up the tops of the two images

• In the layers dialog activate the overlay image by clicking on it (look for the white border)

• Use the Move tool to drag it up so the tops of the two images are aligned

Finishing up

Flatten the blended image into a single layer

• Image - Flatten Image

• Use the Crop tool to remove the unwanted portions of the image

This tutorial was adapted from a Photoshop® tutorial. There may be different and/or better ways to do some of these things. Some of the methods I used were developed from trial-and-error. I try, too, to include some less frequently used techniques if I can. I hope you find this tutorial useful and instructive. - tab

Creating a brush with variable size

When I first started to use GIMP, one of the Photoshop® features I most missed was the ability to resize a brush on-the-fly rather than having to reselect a different size brush or create a new one of the needed size. I searched unsuccessfully for a way to do this.

Recently, as I was looking in the GIMP manual online, I noticed an item 'Creating a brush with variable size'. I hadn't ever noticed this item before, so it's either been recently added or I'm #@%&. At any rate, I'm presenting it here enhanced with screenshots for those of you who would like to make use of this handy feature.

1. Start with opening the Brush dialog by double-clicking on the Brush area in Toolbox, or by File → Dialogs → Brushes. Click on the New Brush button to open the Brush Editor dialog.

   

2. Name your brush at once, 'Variable Round' for instance.
   
   
3. Your brush will appear in the Brush options with a blue corner.
   
4. Now, go File → Preferences → Input Controllers

• Click the Main Mouse Wheel tab.
• Check Enable this controller.
• Scroll through the Events list and select Scroll up (Shift).
• Click on the Edit button to open a window that allows you to assign an action to the selected event.
• 

5. Click on the small triangle next to Context to drop the list down. Scroll through this list and select the context-brush-radius-increase item.
   
6. Do the same to assign the 'context-brush-radius-decrease' action to the 'Scroll down (Shift)' event to decrease the brush size.
7. Click on the Save button in the Brush Editor to save your brush.

I am using a third-party mouse on my iMac and didn't have success with the scroll wheel actions. However, using the Main Keyboard tab I was able to assign increase and decease brush radius to the up- and down-arrow keys. I also used the left- and right-arrow keys to decrease and increase the hardness of the brush.

If you work with a tool that has a 'Brush' option and have selected your Variable Round brush, press the Shift key and you will be able to vary the brush size by using the mouse wheel or the up- and down-arrow keys. This change will be visible in real time in the brush area of the Toolbox and in the Brush Dialog.

Hope you found this useful. --tab

Creating Text on a Sphere with GIMP

Includes -

• Using guides, Text tool, Script-Fu drop shadow, Merging layers, Object mapping

Part 1 - Create a new square image

• Choose the color of the sphere as the Background Color

• File - New

• Set the dimensions to 250 x 250 pixels

Part 2 - The guides

• Image - Guides - New Guide (By Percent) ...

• Select Horizontal from the drop down

• Set Percent at 50%

• Use the same procedure to set a Vertical guide at 50%

Part 3 - The text

• Choose the color you want for your text as the Foreground Color

• Select the Text tool

• In the tool settings, select centered alignment

• Set the text size about 30 pixels

• Click in the image to show the text dialog

• Type the text you wish to appear on the image in the dialog box

• Select the Move tool

• Use the Guides to position your text in the center of the square

Part 3a (Optional) - Add a drop shadow to the text

• Script-Fu - Shadow - Drop Shadow

• I simply used the default settings

Part 4 - Creating the sphere

• In the Layers dialog, right click any layer, select Merge Visible Layers ...

• Select Expand As Necessary

• You should now have a single layer

• Filters - Map- Map Object

• Select the Options tab

• Select Sphere from the drop down

• Check Transparent background

• Check Enable antialiasing

Part 5 - Finishing up

• Hide the Guides

• View - Show Guides (deselect)

You can now easily Copy and Paste into another image

The parameters I used throughout this lesson are a matter of personal preference. Feel free to experiment and have fun.

If you found this lesson useful, a small dontation would be greatly appreciated.