Abstract: There is provided a method, a device (104), and a system (100) for enhancing changes in an image (103a) of an image sequence (103) captured by a thermal camera (102). An image (103a) which is part of the image sequence (103) is received (S02) and pixels (408) in the image that have changed in relation to another image (103b) in the sequence are identified (S04). Based on the intensity values of the identified pixels, a function (212, 212a, 212b, 212c, 212d, 212e) which is used to redistribute intensity values of changed as well as non-changed pixels in the image is determined (S06). The function has a maximum (601) for a first intensity value (602) in a range (514) of the intensity values of the identified pixels, and decays with increasing distance from the first intensity value.

Abstract: A method and an alert discriminator for converting alerts in a video monitoring operation. The method comprises: triggering a candidate alert, in response to detecting, in a stream of thermal images of a scene, a stationary foreground object in the scene; evaluating an intensity of the detected stationary foreground object in relation to a background intensity; and in response to the intensity of the detected stationary foreground object being above the background intensity, converting the candidate alert to an actual alert.

Abstract: A method and a system for filtering thermal image data. The method comprises: capturing thermal image data by a thermal image detector; forming a signal distribution of intensity values; identifying a first part in the signal distribution of intensity values, the first part being a peak having an intensity width equal to or smaller than a predetermined intensity span being based on a resolution parameter of the thermal image detector; identifying a second part having an intensity width larger than the predetermined intensity span; determining an intensity range between the first part and the second part; and filtering, if the intensity range is larger than a predetermined minimum intensity range, the thermal image data by excluding thermal image data forming part of the first part.

Abstract: A method for pseudo coloring of a digital single-channel image is disclosed. The method comprises acquiring a single-channel image having an intensity distribution, forming a first channel of a multi-channel image by performing a first histogram equalization of the intensity distribution, forming a second channel of the multi-channel image by performing a second, different, histogram equalization of the intensity distribution, wherein the first channel and the second channel of the multi-channel image represent different components of a color model. An arrangement for providing a pseudo coloring of a digital single-channel image is also disclosed, and a monitoring thermal camera system comprising such an arrangement.

Abstract: A method and a controller for controlling a video processing unit to facilitate detection of newcomers in a first environment. The method comprises: capturing a thermal image of a human object in the first environment, the first environment being associated with a first climate; calculating, based on the thermal image, a thermal signature of a portion of the human object; determining that the human object has entered the first environment from a second environment when the thermal signature of the portion of the human object deviates from a predetermined thermal signature associated with the first environment, wherein the second environment is associated with a second, different, climate; and controlling the video processing unit to prioritize the human object over other human objects when processing video frames depicting the human object together with the other human objects.

Abstract: An apparatus is disclosed for structural fixed pattern noise reduction in a video stream. A method may include, for each target pixel in a first image frame, defining a first target pixel patch, and defining a first search area comprising the first target pixel patch; for each pixel in the first search area, comparing a first pixel patch around the pixel with the first target pixel patch, and using the pixel when calculating an average for the target pixel. The method may include, in a second image frame, localizing a second target pixel, and defining a second search area comprising the second target pixel; for each pixel in the second search area, comparing a second pixel patch around the pixel of the second search area with the first target pixel patch, and using the pixel in the second search area when calculating an average for the target pixel.

Abstract: A method for increasing enhancing local contrast in a thermal image for a class of objects having a thermal characteristic is provided. The method including providing thermal image data representing a first thermal image, where the first thermal image is acquired by an absolute calibrated thermal imaging system, redistributing the thermal image data having a first intensity distribution into a second intensity distribution using a predetermined redistribution function, where the predetermined redistribution function is based on the thermal characteristic, such that the local contrast is enhanced for the class of objects, outputting the redistributed thermal image data as the thermal image. An apparatus for enhancing local contrast in a thermal image for a class of objects having a thermal characteristic is further provided.

Abstract: An apparatus is disclosed for structural fixed pattern noise reduction in a video stream. A method may include, for each target pixel in a first image frame, defining a first target pixel patch, and defining a first search area comprising the first target pixel patch; for each pixel in the first search area, comparing a first pixel patch around the pixel with the first target pixel patch, and using the pixel when calculating an average for the target pixel. The method may include, in a second image frame, localizing a second target pixel, and defining a second search area comprising the second target pixel; for each pixel in the second search area, comparing a second pixel patch around the pixel of the second search area with the first target pixel patch, and using the pixel in the second search area when calculating an average for the target pixel.

Abstract: A method for pseudo coloring of a digital single-channel image is disclosed. The method comprises acquiring a single-channel image having an intensity distribution, forming a first channel of a multi-channel image by performing a first histogram equalization of the intensity distribution, forming a second channel of the multi-channel image by performing a second, different, histogram equalization of the intensity distribution, wherein the first channel and the second channel of the multi-channel image represent different components of a color model. An arrangement for providing a pseudo coloring of a digital single-channel image is also disclosed, and a monitoring thermal camera system comprising such an arrangement.

Abstract: There is provided a method for pre-processing a video stream for subsequent motion detection processing. The method comprises receiving a video stream of images, wherein each image in the video stream is represented by a first plurality of bits; enhancing the video stream of images by, for each image in the video stream: comparing the image to at least one previous image in the video stream so as to identify pixels where the image differs from the at least one previous image in the video stream, enhancing the image in those pixels where the image differs from the at least one previous image in the video stream; and converting the enhanced video stream of images so as to produce a converted video stream of images for subsequent motion detection processing, wherein each image in the converted video stream is represented by a second plurality of bits being lower than the first plurality of bits.

Abstract: A method for increasing enhancing local contrast in a thermal image for a class of objects having a thermal characteristic is provided. The method including providing thermal image data representing a first thermal image, where the first thermal image is acquired by an absolute calibrated thermal imaging system, redistributing the thermal image data having a first intensity distribution into a second intensity distribution using a predetermined redistribution function, where the predetermined redistribution function is based on the thermal characteristic, such that the local contrast is enhanced for the class of objects, outputting the redistributed thermal image data as the thermal image. An apparatus for enhancing local contrast in a thermal image for a class of objects having a thermal characteristic is further provided.

Abstract: There is provided a method for pre-processing a video stream for subsequent motion detection processing. The method comprises receiving a video stream of images, wherein each image in the video stream is represented by a first plurality of bits; enhancing the video stream of images by, for each image in the video stream: comparing the image to at least one previous image in the video stream so as to identify pixels where the image differs from the at least one previous image in the video stream, enhancing the image in those pixels where the image differs from the at least one previous image in the video stream; and converting the enhanced video stream of images so as to produce a converted video stream of images for subsequent motion detection processing, wherein each image in the converted video stream is represented by a second plurality of bits being lower than the first plurality of bits.