Imaging system and imaging method

• US 8,254,688 B2
• Filed: 05/02/2005
• Issued: 08/28/2012
• Est. Priority Date: 05/10/2004
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Mizuno, Seiichiro, Sugiyama, Yukinobu
• Primary Examiner(s): Mehta, Bhavesh
• Assistant Examiner(s): Park, Edward
• Application Number:
  US11/596,070
• Publication Number:
  US 20080253616A1
• Time in Patent Office: 2,675 Days
• Field of Search: 382/100, 382/103, 382/105, 382/106, 382/107, 382/181, 382/190, 382/231, 382/254, 382/308
• US Class Current: 382/190
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 20/625 License plates
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

The present invention relates to, for example, an image pickup system having a structure capable of imaging a subject at a low power consumption and a low cost even when the subject may be dark. The image pickup system comprises an image pickup device, a peak position detecting section, a partial image acquiring section, and a partial image operating section. The image pickup device outputs image data that represents the two-dimensional intensity distribution of light incident on a photodetecting section, and outputs light intensity profile data that represents the one-dimensional intensity distribution of the incident light in each of first and second directions in the photodetecting section. The peak position detecting section detects a light intensity peak position in the two-dimensional intensity distribution of the light incident on the photodetecting section in the image pickup device, based on the light intensity profile data outputted from the image pickup device. The partial image acquiring section acquires a partial image from an entire image that can be imaged by the image pickup device so that the light intensity peak position detected by the peak position detecting section is made a specific position for the partial image in the entire image. The partial image operating section integrates the acquired partial image.

Claims

1. An image pickup system comprising:

an image pickup device having a photodetecting section with a plurality of pixels arranged two-dimensionally therein, said image pickup device outputting image data that represents the two-dimensional intensity distribution of light incident on said photodetecting section, and outputting light intensity profile data that represents the one-dimensional intensity distribution of the incident light in each of a first direction and a second direction different from the first direction in said photodetecting section;

a peak position detecting section acquiring the light intensity profile data in the respective first and second directions outputted from said image pickup device and detecting a light intensity peak position in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device based on the acquired light intensity profile data;

a partial image acquiring section acquiring a partial image from an entire image that can be imaged by the image pickup device so that the light intensity peak position detected by said peak position detecting section is made a specific position for the partial image in the entire image; and

a partial image operating section integrating the partial image acquired by said partial image acquiring section.

2. An image pickup system according to claim 1, wherein said peak position detecting section detects a plurality of light intensity peak positions in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device, and

wherein said partial image operating section magnifies or demagnifies the partial image so that the distance between the plurality of light intensity peak positions is made constant, and thereafter integrates the magnified or demagnified partial image.

3. An image pickup system according to claim 1, wherein said peak position detecting section detects a plurality of light intensity peak positions in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device, and

wherein said partial image operating section rotates the partial image so that the direction of straight lines connecting the plurality of light intensity peak positions with each other is made constant, and thereafter integrates the rotated partial image.

4. An image pickup system according to claim 1, wherein said partial image acquiring section extracts only image data corresponding to the partial image among the image data read out from said image pickup device.

5. An image pickup system according to claim 1, wherein said partial image acquiring section reads out only image data corresponding to the partial image from said image pickup device.

6. An image pickup system according to claim 5, wherein the time period during which said partial image acquiring section acquires the partial image from said image pickup device and the time period during which said peak position detecting section acquires the light intensity profile data from said image pickup device are overlapped at least partially with each other.

7. An image pickup method using an image pickup device having a photodetecting section with a plurality of pixels arranged two-dimensionally therein, said image pickup device outputting image data representing the two-dimensional intensity distribution of light incident on the photodetecting section and outputting light intensity profile data representing the one-dimensional intensity distribution of the incident light in each of a first direction and a second direction different from the first direction in said photodetecting section, said method comprising:

a peak position detecting step of acquiring the light intensity profile data in the respective first and second directions outputted from said image pickup device, and of detecting a light intensity peak position in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device based on the acquired light intensity profile data;

a partial image acquiring step of acquiring a partial image from an entire image that can be imaged by said image pickup device so that the light intensity peak position detected in the peak position detecting step is made a specific position for the partial image in the entire image; and

a partial image operating step of integrating the partial image acquired in the partial image acquiring step.

8. An image pickup method according to claim 7, wherein the peak position detecting step detects a plurality of light intensity peak positions in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device, and

wherein the partial image operating step magnifies or demagnifies the partial image so that the distance between the plurality of light intensity peak positions is made constant, and integrates the magnified or demagnified partial image.

9. An image pickup method according to claim 7, wherein the peak position detecting step detects a plurality of light intensity peak positions in the two-dimensional intensity distribution of the light incident on said photodetecting section in said image pickup device, and

wherein the partial image operating step rotates the partial image so that the direction of straight lines connecting the plurality of light intensity peak positions with each other is made constant, and integrates the rotated partial image.

10. An image pickup method according to claim 7, wherein the partial image acquiring step extracts only image data corresponding to the partial image among the image data read out from said image pickup device.

11. An image pickup method according to claim 7, wherein the partial image acquiring step reads out only image data corresponding to the partial image from said image pickup device.

12. An image pickup method according to claim 11, wherein the time period for acquiring the partial image from said image pickup device in the partial image acquiring step and the time period for acquiring the light intensity profile data from said image pickup device in the peak position detecting step are overlapped at least partially with each other.