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That will depend on your camera.

Starting with Version 2.0, you can directly capture snapshots from a webcam or video camera. In the case of a video camera, you may also need to use a video capture device.

Otherwise, you will need to copy the photos from the camera to someplace on your computer in order for the software to find them. You can generally do this via a USB cable supplied with the camera or using a memory card (assuming your computer has a memory card reader).