Aperture is a photo editing program developed and marketed by Apple. The program is designed to work on Mac desktop and laptop computers. In addition to basic color correction and exposure compensation, you can also combine multiple images onto a single page in a design or layout of your choice. Aperture is not one of the programs included when you buy your Mac computer. It must be purchased as separate program
Select the images you want to combine in the program. Select "New Book" and, in the subsequent dialog box, change the book type to "Custom."
Select "New Theme" and enter the dimensions for your final image. Click "OK," select "Choose Theme" and the program will generate a page with standard layout. Edit the layout to fit your objectives.
Add the images to the layout by dragging and dropping them into the page. Click "Print" when you have placed all the images onto the page and select "PDF" as the output. Select "Save PDF to Aperture" from the drop-down menu. Select the location where you want to save the final image on your computer.