Method for enhancing the performance of a video camera

A video camera capable of switching between night-mode operation and day-mode operation, comprising:

• an image sensor acquiring a first sequence of images without a filter setup arranged in front of an image sensor and without any IR-cut filter arranged in front of the image sensor, i.e., with the video camera operating in night-mode,
• the image sensor acquiring a second sequence of images with the filter arranged in front of the image sensor, the filter setup comprising an IR-transmission filter of known transmission characteristics and having a transmission in the IR-region of at least 30% and below 100% and spatially uniform transmission over its active area such that every pixel of the image sensor will be affected uniformly, wherein the second filter setup has a transmission of visual light of 100% and wherein the first and second sequences of images are consecutive or interleaved,
• an actuation mechanism for transferring the filter setup to and from a position in front of the image sensor,
• a processor for receiving the first and the second sequences of images to calculate a contribution of visual light in images in the first sequence of images and the second sequence of images, and utilizing an assessment of the calculated contribution to improve the performance of the video camera by, switching the video camera from night-mode to day-mode based on the contribution of visual light in the images in the first sequence of images and the second sequence of images, or to deduce and add color information to images acquired with full or partial transmission of IR-radiation to the image sensor based on the contribution of visual light in the images in the first sequence of images and the second sequence of images.