Tech bytes for tea?

Composite two photos seamlessly together using GIMP.

Now that you have learnt about Layers and Layer Masks, there are many tasks and effects that you can do using them. I had some questions from readers about how to apply certain effects to their photos so that they can use them in their websites.

Morning dew on flowers outside our hotel in Provence, France

Fading to white allows captions to be added.

Fading a photo to white (or any other colour)

This is easy. After opening the photo in GIMP, activate the BlendTool in the Toolbox.

The Blend, Move and Paintbrush tools are in the Toolbox.

In the Tool Options below the Toolbox, click on the rectangle beside the “Gradient” label and from the dropdown list of options, select “FG to Transparent” gradient.

Click on the Foreground Swatch in the Toolbox and select white from the “Change Foreground Color” dialog box that pops up. If you want the photo to fade to black, red or any other colour instead of white, simply select that colour and set that as the Foreground colour.

Now move the cursor to the image window and drag it from the left side of the photo to the right. A gradient going from pure white to nothing is overlaid onto the photo so that it appears as if the photo is fading into white. If you are not satisfied with the fading, press Ctrl-Z to undo and try dragging again. Trial and error is the best way to get your ideal fading effect.

To fade in more gradually, drag further. You can of course drag from right to left or drag vertically or diagonally – depending on how you want the fading effect to appear.

The disadvantage of this quick-and-dirty method is that the gradient is added directly onto the photo. Once you’ve saved and closed the file, you can’t adjust the fading effect to reveal more of the original photo anymore.

Applying the gradient on a separate layer

Here’s a non-destructive approach that allows the fading effect to be tweaked six months down the line.

Instead of applying the gradient directly to the photo in the Background layer, apply it to a new empty layer above the Background layer. This way, none of the pixels in the original photo in the Background layer is changed or “destroyed”. The fading effect can be changed anytime in the future by replacing or modifying the colour and gradient in the upper layer.

Here are the steps.

Apply the gradient to an empty layer above the photo.

Add a new layer by clicking the icon at the bottom left corner of the Layers dialog. In the “New Layer” dialog box that pops up, select the radio button for “Transparency” option under Layer Fill Type and press the OK button.

A new empty layer is added above the original photo in the Background layer.

Use the Blend Tool to add the gradient to the new empty layer.

The result is that the photo appears to fade into white. You can further finetune the overall effect by using the Move Tool from the Toolbox to move either the photo in the Background layer or the gradient in the upper layer.

Simply activate the Move Tool from the Toolbox, click to select the layer you want to move in the Layers dialog, and drag in the image layer to make the move. You may find it easier to first change the default option of the Move Tool to “Move the active layer” to better control which layer you want to move.

Merging two photos into each other (non-destructively)

Little house on the prairie? More like ruins in a field of lavender.

This intelligent Spaniel named Bugis lives on the lavender fields of the Valensole plateau.

Pleasant memories from our drive through Valensole in Provence

To merge two photos into each other, simply place one photo as a layer above the other photo. Add a layer mask to the upper layer and use the Blend Tool to apply a gradient to the layer mask. The two photos will appear to blend into each other.

Here are the steps.

Open the first photo in GIMP. The photo resides in the Background layer which is the only layer in the Layers dialog for the moment. Bring in the second photo as a new and separate layer by using the “File > Open as Layers” command from the main menu. The new layer sits above the first photo in the Background layer.

Right-click the image thumbnail for the upper layer in the Layers dialog. In the pop-up menu, select “Add Layer Mask”. In the Add Layer Mask dialog box that pops up, press the Add button – any of the options in the dialog box for initialising the layer mask is fine since we will be modifying the layer mask immediately after creating it.

Press “D” on the keyboard to reset the foreground and background colours to black and white respectively.

Activate the Blend Tool from the Toolbox using any of the three “FG to BG” gradients in the Tool Options. Because the layer mask is active, dragging the Blend Tool in the image window will add the gradient to the layer mask instead of the white layer itself. The layer mask hides part of the photo in the upper layer based on the gradient in the layer mask. The result is that the two photos appear to fade into each other.

Again, none of the pixels in the two photos are altered or “destroyed”. The fading effect can be changed anytime in the future by modifying the gradient in the layer mask of the top layer.

I've modified the layer mask by painting with the Paintbrush Tool.

You can further modify the blending by using the Paintbrush Tool from the Toolbox to paint either black or white into the layer mask. Remember – white reveals the pixels in the upper layer while black hides. Shades of gray makes the pixels in the upper layer translucent.

As before, you can also use the Move Tool to move either of the photos around.