Digital cameras have changed the way nearly everyone takes pictures, because digital cameras are easy to use and can hold thousands of images. After a vacation, this can give you a library of hundreds of pictures, making it difficult to choose only a few that you want to print or make into a computer desktop background. A photo collage is a popular solution to this issue and you can create a collage using Google Picasa.
Open your web browser and download Google Picasa, if you do not already have it installed. Save the Picasa install utility.
Double-click the Picasa setup utility after it completes downloading to install. Follow the installation wizard steps. When Picasa completes installation, it will automatically ask to search your computer for pictures.
By default, Picasa does not support GIF files, and during this initial phase and it will not add your GIF files to the album views. We will fix this issue in the next step after the initial import is completed.
Click on "Tools" in the top menu of Picasa and select "Options." Click on the "File Types" tab and check the check box next to GIF. Click "OK" when completed.
Picasa will now search your computer and drives again and will now add your GIF images. If Picasa did not find your GIF images, then click "File" in the top menu and select "Add folder to Picasa" and navigate to the folder with your desired GIF images.
Locate the folder containing the collection of pictures you want to use in your collage. Picasa makes this easy as all the folders are listed in the left side of the screen under the "Folders" section.
Click the the "Create Collage" icon, which is the icon just below the folder name in the folder preview window. As you move your mouse over the icons you will see small blue text appear above the icons. The second icon from the left is the collage icon and the text reads "Create Photo Collage."
Move and arrange the photos in the collage screen to your liking. The default arrangement you see initially is Picasa's random attempt. You can have Picasa try again by clicking the "Scramble Collage" or "Shuffle Pictures" buttons at the bottom of the screen.
Click the "Get more..." button which is on the left side of the screen if you want to include pictures from other folders in your collage. The same process as in Step 5 applies. Just locate the other folder and click the "Create Collage" icon. You are taken back to the Collage tab and your new pictures are in the preview window on the left. Click on the new picture or pictures you just added and click the green "+" button next to the "Get more..." button. Your new pictures are now added to the collage.
Click the "Create Collage" button on the bottom left of the screen when you are satisfied with the arrangement of the pictures. This will create the collage image for you and it is automatically saved in the "Projects" section of Picasa's left navigation screen in the "Collages" heading. You can always go back and edit the collage this way.