Produced by KelbyOne

Merging Photos With Photoshop

SHARE
, / 4101 1

Adobe Photoshop CS3 is an exciting new release, and after working with it for a while, you realize just how comprehensive and deep of an upgrade it really is. Not only are there several great new features but there are significant improvements to existing features, as well. One area that has received both an upgrade and new functionality is in the merging of different photos to create a multi-image panorama or image blend.

In this tutorial, we’ll take a look at the vastly improved Photomerge and the new Auto-Align Layers and Auto-Blend Layers features (which use the same new technology that makes Photomerge so much better than it used to be). We’ll also investigate the image stack feature and reveal a quick way to fix a blown-out, overcast sky.

If you’d like to download the images used in this tutorial to practice these techniques, visit www.layersmagazine.com/downloads.html.

Photomerge: New and Improved!

Step 1 Photography Tips for Better Photomerge Results

Your Photomerge results will be much better if you create your files in a specific way. Although a tripod and (sometimes) a special panoramic tripod head are good for precision results, they’re not necessary (all of the images in this article were photographed handheld). More importantly, you need to provide enough overlapping area between each exposure so the software has plenty of information to consider when it creates the merger. When photographing the scene, try and shoot the images so there is at least a 30% overlap between the photos (I usually use more than 50% overlap).


Colored overlays show the overlapping areas between the photos.

Step 2 Access Photomerge

The results of the new and improved Photomerge are remarkably better than the previous versions. So much better, in fact, that you may find yourself happily indulging in a period of Photomerge rediscovery, especially if you were ever frustrated by some of the random blending errors and post-merge touch-ups required in the CS and CS2 version. Accessing this feature is the same as in previous versions of the program: From within Photoshop, choose File>Automate>Photomerge. From Adobe Bridge, select the image thumbnails you want to use for the merged image and choose Tools>Photoshop>Photomerge.

Step 3 Choose Files and Layout Method

In the Photomerge dialog, choose the files you want to use (if you’ve accessed Photomerge from Bridge, it will display the files you selected). The Auto Layout method is the default and is usually the best choice if you’re not sure which of the other methods will work for your group of images. Auto analyzes the files to determine the optimum way to fit them together. Depending on the images, it will apply either a Perspective or Cylindrical layout. The blend results will be much better if you leave Blend Images Together checked at the bottom of the dialog.

Step 4 Layout Methods: Perspective and Cylindrical

Perspective designates one of the source images (by default, the middle image) as the reference image. The other files are then transformed (repositioned, stretched, or skewed, as necessary) so that overlapping content across the layers is matched. Cylindrical arranges individual images as if they were on an unrolled cylinder and also matches overlapping content. The center image is used as the reference. Cylindrical is best suited for creating wide panoramas. It also reduces the bowtie-shaped distortion that sometimes occurs with the Perspective layout. When Blend Images Together is checked, the resulting merge will be created with precise layer masks and exposure blending.

Step 5 Layout Methods: Reposition Only and Interactive Layout

Reposition Only aligns the layers and matches overlapping content using layer masks and exposure blending, but it doesn’t stretch or skew any of the source layers. Interactive Layout is essentially the old Photomerge assembly dialog with functionality removed (the Cylindrical option) rather than added. The automatic methods are so good, however, that there are no compelling reasons to use the Interactive Layout. If you want to purposefully create abstract merges with misaligned edges (which can look cool), then uncheck Snap to Image and use the Select Image and Rotate Image tools to rearrange your photos as desired.

{module:ads/large_rectangle}

Auto-Align Layers & Auto-Blend Layers

Step 1 Blending Multi-layered Files

The underlying technology that makes the new Photomerge work so well is also available as a separate set of commands for aligning and blending layer content. These commands, Auto-Align Layers and Auto-Blend Layers, both found under the Edit menu, can be used with panoramas, à la Photomerge, or with other types of images that you want to blend. We’ll take a look at creating a panorama with these tools using the Japanese temple images above. And then we’ll use another image to explore a technique for automatically blending layers.

Step 2 Create Layered File from Source Images

The first Step is to open your source images and arrange them as layers in a single file. Choose one of the files as the main image and double-click on the Background layer to turn it into a regular layer. Now use the Move tool (V), hold down the Shift key, and drag-and-drop the other images onto this file. You can also choose File>Scripts>Load Files Into Stack to automate this process. In the Load Layers dialog, choose the source files but do not check the Attempt to Automatically Align Source Images option or the Create Smart Object after Loading Layers option.

Step 3 Choose and Lock Reference Layer; Auto-Align & Blend

Click on one of the layers to choose it as a reference point for the alignment (for the temple image, use the center view, Temple-2), and then click the Lock All icon (the padlock) at the top of the Layers panel. Command-click (PC: Ctrl-click) on the other layers in the Layers panel to select all of them and choose Edit>Auto-Align Layers. In the Auto-Align Layers dialog choose Auto and click OK. When the auto alignment is done, choose Edit>Auto-Blend Layers. When the blending is done, you’ll see that precise layer masks have been added to the Layers panel.

Step 4 Convert to Smart Object; Fix Lens Distortion

Unlock the reference layer by selecting it in the Layers panel and clicking the Lock All icon. Click on the top layer and then Shift-click the bottom layer to select them all. Control-click (PC: Right-click) on one of the layers and choose Convert to Smart Object. The three layers are grouped into a single smart object. Now we need to fix the fact that the temple isn’t level and seems to be tilted back away from the camera. Choose Filter>Distort>Lens Correction. Go to the Transform section, enter –10 for the Vertical Perspective, 1.00° for Angle, and lick OK.

Step 5 Restore Cloudy Sky Detail; Add Cloudy Sky Layer

In order to get a good exposure for the temple, the cloudy sky ended up washed out, so I took a few photos of just the cloudy sky above the temple to blend in later. To do this, open the Cloudy Sky file and use the Move tool to drag it onto the composited temple image. Position it so the new sky covers all of the washed-out sky. At the top of the Layers panel, change the blend mode to Multiply. Don’t worry about the uneven edge at the top of the sky; we’ll crop that out at the end.

Step 6 Add a Layer Mask

Use the Lasso tool (L) with the Feather set to 0 in the Options Bar to make a loose selection of the entire sky extending down a little over the mountain. Mask the sky from the lower part of the image by choosing Layer>Layer Mask>Reveal Selection. Now use the Rectangular Marquee tool (M) to select the bottom half of the mask. Choose Filter>Blur>Gaussian Blur and enter a Radius value of 40 to 70 pixels to create a soft transitional edge that disguises the edge of the mask. Touch up the layer mask with a large, soft-edged brush if necessary.

Step 7 Duplicate; Flatten Layers; Crop

Choose File>Save As to save this layered version as your master file. Then, choose Image>Duplicate, click the Duplicate Merged Layers Only checkbox to flatten the layers in the copy file, and click OK. Choose the Crop tool (C) and drag a cropping box around the image to exclude the uneven edges in the sky and along the bottom and sides. Press Return (PC: Enter) to apply the crop.

Collaging with Auto-Align & Blend

Step 1 Create Image Stack; Auto-Align Layers

The Auto-Align Layers and Auto-Blend Layers features are also great for creating seamless collages of a single scene where certain elements change their position within the setting. In this example, I took two photos of my daughter Fiona to create an imaginary scene where she meets herself. First, create an image stack, either manually or by using the image stack script, as shown in Step 2 of the temple exercise. Click on one of the layers to designate it as a reference for the alignment. Then, Shift-click on the other layer to select it. Choose Edit>Auto-Align Layers. In the dialog, choose Auto.

Step 2 Auto-Blend Layers; Crop

Now choose Edit>Auto-Blend Layers, and sit back and enjoy the results. Select the Crop tool to crop off the uneven edges and begin pondering all the interesting creative possibilities for these cool new Photoshop CS3 features! (Note: On images with people in them, the angle of view of the scene should be the same for all the layers. Otherwise, perspective transformations could be introduced which could cause distortion that would look odd when applied to people. For some images you might need to choose Reposition Only in the Auto-Align Layers dialog.)

ALL IMAGES SEÁN DUGGAN