Image processing apparatus

• US 20020030735A1
• Filed: 09/13/2001
• Published: 03/14/2002
• Est. Priority Date: 09/14/2000
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Yamada, Masahiro
• Granted Patent: US 7,365,779 B2
• Time in Patent Office: Days
• US Class Current: 348/47
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 2300/105 using multiple cameras
• CPC Class Codes: B60R 2300/107 using stereoscopic cameras
• CPC Class Codes: B60R 2300/207 using multi-purpose displays, e.g. camera image and navigation or video on same display
• CPC Class Codes: B60R 2300/30 characterised by the type of image processing
• CPC Class Codes: B60R 2300/804 for lane monitoring
• CPC Class Codes: G01C 3/00 Measuring distances in line of sight; Optical rangefinders tapes, chains or wheels for measuring length G01B3/00; active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves, G01S17/48
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

The invention provides an image processing apparatus that can reduce the memory capacity of a memory forming part of the image processing apparatus and can correct the optical axis misalignment of a video camera in a simple manner. The image processing apparatus 10, which comprises a video camera 11, a memory 13 for storing an image signal supplied from the video camera, and a CPU 14 for performing prescribed processing on the image signal read out of the memory, includes a selective writing means 12 for selecting only a designated portion of the image signal in accordance with a select command C from the CPU, and for writing only the selected portion as a selected image signal S′ into the memory 13. The image processing apparatus further includes a switching means for selecting the pixel data to be stored in the memory by switching between high-density pixel data covering a designated range centralized in a horizontal direction of the image and relatively low-density pixel data covering a full image range. The switching means is capable of switching in accordance with vehicle speed.

Claims

1. An image processing apparatus comprising a video camera for shooting an object, a memory for storing an image signal supplied from said video camera, and a CPU for performing prescribed processing on said image signal read out of said memory, wherein

said image processing apparatus includes selective writing means for selecting, in accordance with a select command from said CPU, only a designated portion of said image signal supplied from said video camera, and for writing only said selected portion as a selected image signal into said memory.

2. An image processing apparatus as claimed in claim 1, wherein an image signal representing a portion corresponding to an area necessary for said prescribed processing is selected in accordance with said select command and taken as said selected image signal, said area being an area lying within an imaging surface defined by said imaging signal supplied from said video camera.

3. An image processing apparatus as claimed in claim 2, wherein optical axis misalignment of a stereo camera forming said video camera is measured and stored in advance as an optical axis misalignment amount, and the area necessary for said prescribed processing is shifted within said imaging surface in accordance with said optical axis misalignment amount.

4. An image processing apparatus as claimed in claim 2, wherein an image signal representing a portion corresponding to a lower half of said imaging surface is selected and taken as said selected image signal.

5. An image processing apparatus as claimed in claim 2, wherein of a plurality of pixels forming said imaging surface, pixels in a horizontal axis direction of said imaging surface are thinned off, and a resulting image signal is taken as said selected image signal.

6. An image processing apparatus as claimed in claim 2, wherein of a plurality of pixels forming said imaging surface, pixels in a vertical axis direction of said imaging surface are thinned off, and a resulting image signal is taken as said selected image signal.

7. An image processing apparatus as claimed in claim 2, wherein when said imaging surface is split into a center area and left and right areas respectively located to the left and right of said center area, image signals representing portions corresponding to said left and right areas are respectively selected, and each of said signals is taken as said selected image signal.

8. An image processing apparatus as claimed in claim 2, wherein an upper image signal representing a portion corresponding a designated area in an upper half of said imaging surface and a lower image signal representing a portion corresponding a designated area in a lower half of said imaging surface are respectively selected, and each of said signals is taken as said selected image signal.

9. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, comprising:

switching means for selecting the pixel data to be stored in said memory by switching between high-density pixel data covering a designated range centralized in a horizontal direction of said image and relatively low-density pixel data covering a full image range.

10. An image processing apparatus as claimed in claim 9, wherein said switching means performs switching so that when vehicle speed is not higher than a predetermined speed, said relatively low-density pixel data covering said full image range is stored in said memory, while when said vehicle speed is higher than said predetermined speed, said high-density pixel data covering said designated range centralized in the horizontal direction of said image is stored in said memory.

11. An image processing apparatus as claimed in claim 9, wherein said designated range centralized in the horizontal direction of said image is variable within a range of 0% to 100% of horizontal length, and said designated range is varied continuously.

12. An image processing apparatus as claimed in claim 9, wherein said designated range centralized in the horizontal direction of said image is varied linearly and continuously within a range of 0% to 100% of horizontal length in accordance with vehicle speed.

16. An image processing apparatus as claimed in claim 15, wherein said switching means performs said switching in accordance with vehicle speed.

18. An image processing apparatus as claimed in claim 17, wherein said left and right split ranges are equal in size.

19. An image processing apparatus as claimed in claim 17, further comprising switching means for optionally selecting the pixel data to be stored in said memory by switching between the high-density pixel data taken from said one range and the high-density pixel data taken from the other range.

13. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, wherein

high-density pixel data is taken from a designated range centralized in a horizontal direction of said image, and relatively low-density pixel data from the remaining range, and said taken pixel data are stored in said memory.

14. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, wherein

relatively low-density pixel data is taken from a designated range centralized in a horizontal direction of said image, and high-density pixel data from the remaining range, and said taken pixel data are stored in said memory.

15. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, comprising:

first means for taking high-density pixel data from a designated range centralized in a horizontal direction of said image and relatively low-density pixel data from the remaining range;

second means for taking relatively low-density pixel data from said designated range centralized in the horizontal direction of said image and high-density pixel data from the remaining range; and

switching means for selecting the pixel data to be stored in said memory by switching between the pixel data taken out by said first means and the pixel data taken out by said second means.

17. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, comprising:

means for splitting said image between left and right ranges in a horizontal direction thereof, and for taking high-density pixel data only from one of said ranges and storing said high-density pixel data in said memory.

20. An image processing apparatus which stores pixel data from an imaging device into a memory, and obtains an image by processing said stored pixel data, comprising:

means for setting a prescribed range in a horizontal direction of said image, and for taking high-density pixel data from said prescribed range and relatively low-density pixel data from the remaining range and storing said taken pixel data in said memory.

21. An image processing apparatus as claimed in claim 20, wherein said prescribed range is freely movable in the horizontal direction of said image.