Blend two Images with the GIMP

I use the Gimp to edit and produce artwork. For a project I wished to blend the edge between two images.

Whilst working on a recent slider for a website. The images I had to work with were either the wrong orientation or just not quite long enough to be used as single images.

I wanted to join a couple of images together to create a composite image, the full width of the slider. This would also allow me to convey more information on a single slider image view.

Blending two images together to get a smooth transition rather than a hard edge makes it more appealing. Even if the edge is only a few pixels it will be easier on the eye.

Using the Gimp I took two images for a slider and blended the join between the two to create a fade between them.

Here I am using two pictures from Bergen. To begin with in a new image I added the two images, one per layer, leaving the background untouched. To make this work best an overlap of the two images is required.

Blend images with the Gimp: initial layers

The layers are shown in the Layers Window: the image of the troll, the view of Bergen from Mount Fløyen and the generic background layer.

Blend images with the Gimp: layers window

In the layers window, for each of the layers, right click and select to Add Layer Mask.

Blend images with the Gimp add layer mask to layer

Ensure that the option White (full opacity) is selected

Blend images with the Gimp add layer mask

With the layer masks added again right click to view the properties, check to ensure that the check box for Edit Later Mask is ticked.
image here

Blend images with the Gimp confirm edit layer mask set

From the tools window select the blend tool. The foreground and background colours should be black and white respectively.

Blend images with the Gimp select blend tool

Between the transition of the two images drag the blend tool line, if horizontal of vertical holding down the ctrl key helps to keep it at 0, 90, 180 or 270 degrees.

Drag as far as you need to create the blended transition. The longer the line the great the overlapping transition.

Blend images with the Gimp layers blended