Abstract: A method estimates a radiance of an object and comprises: obtaining a thermal image of a scene comprising an apparent object region depicting the object; obtaining object data indicative of a location and an extension of an actual object region; determining a representative background radiance; obtaining a blur parameter indicative of a blur radius of a blur spot; determining a pixel value of a sample pixel of the apparent object region; determining for the sample pixel: an object radiance contribution factor based on a number of actual object pixels located within the blur range from the sample pixel, and a background radiance contribution factor based on a number of actual background pixels located within the blur range from the sample pixel; and estimating a diffraction-compensated radiance of the object based on the pixel value of the sample pixel, the representative background radiance, and the object and background radiance contribution factors.

Abstract: A method for thermal image processing comprises obtaining a thermal image depicting a scene comprising objects; identifying a set of apparent object regions, each apparent object region includes a depiction of a respective object which is blurred due to diffraction, and each apparent object region being identified as a contiguous region of pixels having intensities differing from a representative background intensity by more than a threshold intensity, and exceeding a threshold size such that the apparent object region includes an actual object region and a blurred edge region and applying to each object region a contrast enhancement comprising: partitioning the blurred edge region into a background edge region and an object edge region intermediate the actual object region and the background edge region; and setting pixels of the object edge region to a representative object intensity determined from actual object pixels, and pixels of the background edge region.

Abstract: A thermometric camera for determining a temperature of an object in motion comprises a bolometer sensor and circuitry. The bolometer sensor captures a sequence of image frames of the object while the object is moving. The circuitry executes: an object identifying function configured to identify an area corresponding to the object in each image frame of a series of image frames among the sequence of image frames; a combining function configured to combine the identified areas from each image frame in the series of image frames into a stacked image of the object, wherein pixel values in the stacked image of the object are estimated as a sum of pixel values of the corresponding pixels in the image frames in the series of image frames; and a temperature determining function configured to determine the temperature of the object in motion from pixel values in the stacked image of the object.

Abstract: A method of detecting a reflection in a first thermal image captured by a thermal image sensor and, a second image is captured by a visible light sensor, near infrared sensor, or short-wave infrared sensor having a field of view which overlaps a field of view of the thermal image. A relationship between coordinates in the thermal image and the second image is determined. A first object is detected in a first position in the thermal image. A candidate image area in a second position in the second image is analysed to determine if anx 10 object equivalent to the first object is present, the second position corresponding to the first position according to the relationship between the coordinates in the thermal image and the second image. In response to a determination that there is no equivalent object in candidate image area, it is determined that first object is a reflection.

Abstract: A method for reducing a dynamic range of an image, whereby first and second images have pixel values of a first bit depth. One or more peak regions and a representative pixel value for each peak region is identified in a histogram of the pixel values in the first image. For pixel values in the first image that are within a peak region, a pixel value difference is calculated as a difference between the pixel value and the representative pixel value of the peak region. For pixel values in the first image that are outside of the peak regions, the pixel value difference is zero. The pixel values of the second image are transformed to reduce the bit depth to a second bit depth. The pixel value differences calculated from the first image are then added to the pixel values of the transformed second image.

Abstract: A device for monitoring a heap of material, comprises circuitry for executing a plurality of functions. A region of interest function, in a thermal video stream captured by a thermal video camera, defines a region of interest covering the heap of material. A reference spatial property setting function, from pixels within a video frame of the thermal video stream, determines a spatial property of the heap of material; and sets the determined spatial property as a reference spatial property. A region of interest adjusting function determines a respective sample spatial property for regions in the thermal video stream; and adjusts the region of interest such that regions exhibiting a sample spatial property above a threshold are included by the region of interest. A temperature monitoring function over time and within the region of interest, monitors a temperature measure; and if it exceeds a predetermined threshold, generates an alarm event.

Abstract: A method of controlling a guard tour of a thermal camera, wherein the thermal camera is a pan-tilt camera or a pan-tilt-zoom camera, comprises the steps of: obtaining a guard tour comprising a plurality of views of an area or facility and a sequence of movements and/or view times of the thermal camera for traversing the plurality of views; controlling the thermal camera to traverse the plurality of views according to the sequence of movements and view times of the guard tour; for each view: extracting a temperature profile based on thermal images from the thermal camera; based on the temperature profile, estimating whether an increased risk of overheating or overcooling exists for the view; and if so, adjusting the sequence of movements and view times of the thermal camera to show the view having an increased risk of overheating or overcooling more frequently.

Abstract: There is provided a method for capturing a sequence of image frames in a thermal camera having a microbolometer detector comprising: capturing a first sequence and a second sequence of image frames with a shutter of the thermal camera being in a closed state and an open state, respectively. While capturing each of the first and the second sequence, an integration time of the microbolometer detector is switched between a plurality of integration times according to one or more repetitions of a temporal pattern of integration times. The method further comprises correcting image frames in the second sequence that are captured when the integration time is switched to a particular position within the temporal pattern of integration times using image frames in the first sequence that are captured when the integration time is switched to the same particular position within the temporal pattern of integration times.

Abstract: A method for temperature calibration and determination of a temperature in a scene. At each time point out of a plurality of time points in a first period of time, collecting an ambient temperature representing a temperature at a first part of the scene and collecting thermal image sensor signal values corresponding to the collected ambient temperatures and relating to the first part. Determine a calibration function based on the collected ambient temperatures and the thermal image sensor signal values corresponding to each of the collected ambient temperatures. In a second period of time, capturing a thermal image of the scene comprising thermal image sensor signal values relating to a second part of the scene and determine a temperature at the second part of the scene based on the calibration function and based on thermal image sensor signal values comprised in the thermal image.

Abstract: The present disclosure relates to a method performed by a people distinguishing system (1) for in an image distinguishing human beings in a crowd. The people distinguishing system identifies (1001) one or more detected objects classified as human beings (2) in an image (3) derived from a thermal camera (10) adapted to capture a scene in an essentially forward-looking angle. The people distinguishing system further identifies at least a first grouping (4) of adjoining pixels in the image, not comprised in the one or more detected human beings, having an intensity within a predeterminable intensity range. Moreover, the people distinguishing system determines (1003) a grouping pixel area (40) of the at least first grouping in the image. Furthermore, the people distinguishing system determines (1004) for at least a first vertical position (yexpected) in the image, based on head size reference data (5), an expected pixel area (xexpected) of a human head at the at least first vertical position.

Abstract: Methods and apparatus, including computer program products, for detecting a problem with a thermal camera. A current contrast value is determined for the thermal camera. It is determined whether the current contrast value deviates from a reference contrast value by more than a predetermined value. In response to determining that the current contrast value deviates from the reference contrast value by more than a predetermined value and for more than a predetermined period of time, an indication of a problem with the thermal camera is provided.

Abstract: Methods and apparatus, including computer program products, for detecting malfunction in a thermal camera. A first average response value is determined for a first shutter image captured by an image sensor in the thermal camera. A second average response value is determined of a second shutter image captured by the image sensor in the thermal camera. The first average response value and the second average response value are compared. In response to determining that the first average response value and the second average response value differ by more than a predetermined value, an indication of a malfunction of the thermal camera is provided.

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: 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.