How you can see objects in IR images?

Answer 1

Your question requires qualification. There is near-IR and far-IR which covers the wide range of wavelengths of IR. IR images are all about us, but our eyes cannot see them. In order to view them, some sort of image converter is required. The near IR band, just beyond what the eye can see, is called Near-IR. In this range, silicon diode detectors do a fairly good job of converting the image signal to an electrical signal. As is the case for a digital camera, an array of Near-IR signal diodes are used to detect the image, which is converted to an array of digital signals. These signals can then be converted to RGB signals, similar to those used for a computer monitor and then viewed. This is a very common method of producing IR image conversion for viewing.

There are also the Night Vision Goggles that are used to view infrared signals at night. The optical detection method is somewhat different, although similar in that a special IR detector is required.

Answer 2

Infrared images capture heat radiation emitted by objects, which is invisible to the human eye. Objects with different temperatures will emit different levels of infrared radiation, allowing them to be detected and displayed in the image. The camera then translates these temperature variations into a visible image that helps visualize the objects.