Flir Systems Ab

Emanuel Johansson

Odd Larson

Stefan F Olsson

Erland Waldreus

Various techniques are provided for a stray light compensation method for an infrared (IR) camera. For example, a stray light compensation method includes: capturing an IR image of a scene by an IR camera, generating a fixed pattern noise estimate FPNestfor time t0 using the captured IR image and a stray light model associated with the IR camera, and performing a fixed pattern noise (FPN) compensation of the captured IR image based on said FPNestto obtain a stray light compensated IR image. The fixed pattern noise estimate may be generated through operations in a frequency domain representation of the captured IR image and the stray light model according to one or more embodiments.

Stray light compensation techniques for an infrared camera

The invention relates to a procedure for mapping when capturing video streams by means of a camera, such as an IR camera, as well as to a computer program and a computer program product. According to the procedure the following items are included: a) at least two reference images are recorded in production against a black-body radiator at the same temperature for two or more separate integration times (block), b) in conjunction with the updating of an offset map, details of the integration time for which the offset map has been updated are stored (block), c) during operation, the actual integration time is compared with the integration time for the most recent updating of the offset map (block), d) the recorded reference image which lies closest to the actual integration time is selected as a reference (block), and e) a compensation per pixel for the change in the integration time is calculated by linear interpolation between the selected reference image and the most recently updated offset map, resulting in a compensation map (block). The integration time can be adapted dynamically by the procedure with access to adequate maps for correction of the offset of constituent pixels.

Procedure for mapping when capturing video streams by means of a camera

The invention relates to a method for compensating motion blur in connection with vibrations in an image recording apparatus (), such as a camera, for stabilization of recorded images, wherein use is made of a reference image. According to the invention, a frame () of a recorded image is selected for image stabilization and the degree of sharpness () in the selected frame is evaluated and compared () with a previously saved reference value () for the degree of sharpness for a previously selected frame. The last chosen frame is used to update () a video sequence and the degree of the sharpness for the last chosen frame is saved () as a new reference value if the degree of sharpness for the last chosen frame is deemed to be better () than or equally as good as the reference value for the degree of sharpness for a previously selected frame. The reference value () for the degree of sharpness for a previously selected frame is saved with reduction () of the value of sharpness and the previously selected frame is used in the video sequence if the degree of sharpness for the last chosen frame is deemed to be worse () than the reference value for the degree of sharpness for the previously selected frame. As a result of the invention, a method which, by relatively simple action, can effectively compensate for motion blur in connection with vibrations is provided.

Method for compensating motion blur in connection with vibrations

An image processing method and to an arrangement for implementing the method. The method includes filtering the original image with a low-pass filter for forming a low-pass filtered image, creating a high-pass filtered image by subtracting the low-pass filtered image from the original image, forming intermediate values from the created high-pass filtered image based on column-wise selection of pixel values in the suppression of column noise and row-wise selection of pixel values in the suppression of row noise, and subtracting formed intermediate values column-by-column and row-by-row from the original image. The arrangement includes a non-linear, one-dimensional digital finite impulse response filter, a computing unit for column-wise or row-wise formation of intermediate values, an image storage unit and a subtraction unit.

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Hjarup, Sweden

Emanuel Johansson