Do I have to use a video capture card to capture images into the computer? What are the advantages of video capture card?

If you are collecting images, it depends on what the video interface is. If it is a USB camera, the computer can directly identify it without the need for an acquisition card. If it is a video interface such as HDMI/SDI/VGA/DVI. Then you must use a video capture card to capture it into the computer. For example, medical diagnostic equipment in hospitals, such as B-ultrasound machines, can only be realistic, how to collect images, take pictures, print and so on. You still need to use the acquisition card. For some video image processing, it is more convenient to use the acquisition card. I hope I can help you.