Method of Controlling an Image Capturing System, Image Capturing System and Digital Camera

Abstract

A method of controlling an image capturing system comprising an interface for receiving an external trigger to capture an image, and an image capturing device provided with a photosensitive area and an array of pixel cells, each pixel cell including a device for generating a signal indicative of the intensity of light falling on an associated part of the photosensitive area, which image capturing device is further provided with readout circuitry for generating an array of pixel values to capture an image frame at a set spatial resolution, such that each pixel value represents an integral of the signal or signals generated in at least one of the pixel cells in an associated one of a number of areas over an exposure time interval, the number of areas being determined by the set spatial resolution, the areas together covering a region of the photosensitive area corresponding to a region in the image, comprises receiving an external trigger to capture an image, and, in response to the external trigger, directing the image capturing device to capture at least two image frames by generating respective arrays of pixel values representing integrals over respective consecutive exposure time intervals. The spatial resolutions of at least two of the captured image frames are set to different values.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present application is a Section 371 National Stage Application of and claims priority of International patent application Serial No. PCT / EP2005 / 052121, filed May 10, 2005, and published as WO 2006 / 119802 in English.BACKGROUND OF THE INVENTION[0002]The invention relates to a method of controlling an image capturing system comprising an interface for receiving an external trigger to capture an image, and an image capturing device provided with a photosensitive area and an array of pixel cells, each pixel cell including a device for generating a signal indicative of the intensity of light falling on an associated part of the photosensitive area, which image capturing device is further provided with readout circuitry for generating an array of pixel values to capture an image frame at a set spatial resolution, such that each pixel value represents an integral of the signal or signals generated in at least one of the pixel cells in an asso...

AI Technical Summary

Benefits of technology

[0013]Because at least two of the captured image frames have different spatial resolutions, there is always at least one image frame with a higher and at least one with a lower resolution. Capturing an image frame with a higher resolution ensures that information with a high spatial frequency is present in the combined final image. Because not all image frames have the same, higher, resolution, the total time needed to capture and read out all the image data is relatively low, however. Because the external trigger, e.g. a user command, results directly in the capture of at least two image frames, the image frames in the series follow each other as closely as possible, saving additional time. The change in settings to set a different resolution is also accomplished automatically in response to the external trigger. Because the image frames are captured separately in such a manner that they may be combined into a combined final image by summation, the combined final image may be composed of image frames with relatively short exposure times, leading to a combined final image with little blur.

[0037]Because the higher resolution image also has a higher noise level, but is only really needed to provide image information with a high spatial frequency, the noise level of the combined final image at lower frequencies is thus reduced. This is advantageous because the human eye is most sensitive at relatively low spatial frequencies.

Problems solved by technology

Because not all image frames have the same, higher, resolution, the total time needed to capture and read out all the image data is relatively low, however.

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