Image acquisition system

• US 7,587,261 B2
• Filed: 01/31/2003
• Issued: 09/08/2009
• Est. Priority Date: 06/28/1996
• Status: Expired due to Fees

• Current Assignee: Metrovideo Incorporated
• Original Assignee: Metrovideo Incorporated
• Inventors: Hopkins, T. Eric
• Primary Examiner(s): DeCady; Albert
• Assistant Examiner(s): Garland; Steven R
• Application Number:
  US10/355,717
• Publication Number:
  US 20030120390A1
• Time in Patent Office: 2,412 Days
• Field of Search: 700/259, 700/276, 382/153, 348/323, 348/314
• US Class Current: 700/259
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 5/10 having a sequence of storage locations each being individually accessible for both enqueue and dequeue operations, e.g. using random access memory G06F5/065 takes precedence
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: H04L 49/90 Buffering arrangements

Abstract

An image acquisition system for machine vision systems decouples image acquisition from the transmission of the image to a host processor by using a programmable imager controller to selectively disable and enable the transmission of data to the host and by using a system of buffers to temporarily store image data pending allocation of memory. This enables the image acquisition system to acquire images asynchronously and to change the exposure parameters on a frame-by-frame basis without the latency associated with the allocation of memory for storage of the acquired image. The system architecture of the invention further permits interruption and resumption of image acquisition with minimal likelihood of missing data. Data throughput is further enhanced by transmitting to the host only that data corresponding to the region of interest within the image and discarding the data from outside of the region of interest at the camera stage.

Claims

1. A system for acquiring and transmitting images to a machine vision system having a host processor that allocates memory space for storage of said images acquired by said system, said system comprising:

image acquisition means responsive to one or more trigger signals to begin acquiring at least a portion of two or more of said images,

memory means holding said memory space for storing at least a portion of data representative of the at least a portion of the two or more of said images acquired by the image acquisition means, and

image transfer means for controlling transfer of said at least a portion of data representative of the at least a portion of the two or more of said images acquired by the image acquisition means from said image acquisition means to said memory means, said image transfer means having buffer memory means for receiving and storing at least a portion of said images pending at least an allocation of said memory space in said memory means by the host processor for said images,

wherein said image acquisition means can operate substantially independently of the allocation of memory by the host processor to acquire the images at any time relative to the allocation of the memory space in said memory means by the host processor, and

wherein the transfer of said at least a portion of data representative of the at least a portion of the two or more of said images acquired by the image acquisition means occurs in response to a release signal or a hold signal generated in response to two or more signals asserted by one or more components forming a portion of a data path for transmission of image data from the image acquisition means to the memory means.

2. A system according to claim 1 wherein said buffer memory means comprises a data FIFO register, said data FIFO register being coupled to receive data representative of said images from said image acquisition means and to release data representative of said images to the host processor in response to a release signal.

3. A system according to claim 2, further comprising direct memory address data transfer means for transferring said image data accumulated in said data FIFO register directly to said memory space allocated by the host processor, whereby said data transfer substantially reduces a number of times said system interrupts the host processor.

4. A system according to claim 2, further comprising pre-processing means separate from the host processor for receiving said image data and for at least partially processing said data without substantially interrupting the host processor.

5. A system according to claim 2, further comprising interrupt means coupled to said data FIFO register and to said image acquisition means for interrupting said acquisition of said images when said data FIFO register is at least substantially full, thereby permitting reliable transfer of data corresponding to said images.

6. A system according to claim 5, wherein said images are composed of a plurality of lines, and wherein said interrupt means is capable of interrupting said acquisition of said images between said lines corresponding to said images.

7. A system according to claim 2, further comprising feedback means coupled between said image acquisition means and said data FIFO register for monitoring a status of said data FIFO register and for transferring an interrupt signal to said image acquisition means to interrupt said acquisition of said images, said feedback means including interrupt means coupled to said data FIFO register for generating said interrupt signal when said data FIFO register is at least substantially full, whereby said interrupt means immediately and temporarily interrupts said acquisition of said images.

8. A system according to claim 1, wherein said buffer memory means comprises a plurality of registers, said plurality of registers being coupled to receive data representative of said images from said image acquisition means in response to said one or more trigger signals and to release data representative of said images to the host processor in response to a release signal.

9. A system according to claim 1, wherein said image acquisition means comprises

photo-sensitive means for acquiring said images in response to said one or more trigger signals containing selected image acquisition parameters, and

programmable control means in circuit with said photo-sensitive means for generating said one or more trigger signals and for programmably altering during acquisition of said images said selected image acquisition parameters.

10. A system according to claim 9, wherein said photo-sensitive means includes a solid state imaging array and said programmable control means includes a programmable imager controller.

11. A system according to claim 9, wherein said programmable control means comprises:

a controller adapted to be programmed with said selected image acquisition parameters and for generating said one or more trigger signals in response to a loading signal, and

parameter loading means coupled to said controller for generating said loading signal and for receiving said image acquisition parameters.

12. A system according to claim 11, further comprising

actuation means for generating an output actuation signal in response to an input command signal, said parameter loading means generating said loading signal in response to said actuation signal, and

parameter memory means, in communication with said parameter loading means, for receiving said image acquisition parameters from the host processor.

13. A system according to claim 9, wherein said programmable control means includes a programmable imager controller circuit, said controller circuit being adapted to be programmed with said image acquisition parameters.

14. A system according to claim 13, wherein said programmable imager controller circuit includes means for receiving said image acquisition parameters in less than or equal to about 2 μ

s.

15. A system according to claim 13, wherein said programmable imager controller circuit includes means for reprogramming said circuit on the fly, in essentially real time.

16. A system according to claim 13, wherein said programmable imager controller circuit operates at a driving frequency, said programmable imager controller circuit comprising means for automatically changing said driving frequency during acquisition of said images.

17. A system according to claim 9, wherein said image acquisition means further includes

actuation means for generating an output actuation signal in response to a command signal,

parameter memory means in communication with said programmable control means for receiving said image acquisition parameters from the host processor, and

a camera loader circuit adapted to receive said selected image acquisition parameters from said parameter memory means and said output actuation signal, for programming said programmable control means with said image acquisition parameters.

18. A system according to claim 9, wherein said buffer memory means comprises one or more vertical registers coupled to said photo-sensitive means for storing optical energy representative of said acquired images, and one or more horizontal registers positioned to receive at least a portion of said optical energy stored in said one or more vertical registers.

19. A system according to claim 18, wherein said photo-sensitive means is adapted to acquire a region of interest corresponding to at least a portion of said images, and wherein said means for transferring transfers a portion of said optical energy corresponding to a portion of said region of interest from said vertical registers into said horizontal registers, further comprising

disabling means for disabling transfer of said optical energy from said one or more horizontal registers during said transfer of optical energy from said one or more vertical registers into said one or more horizontal registers,

whereby said optical energy corresponding to a portion of said region of interest is rapidly transferred from said one or more vertical registers to said one or more horizontal registers without actively removing said stored energy from said one or more horizontal registers.

20. A system according to claim 19, wherein said photo-sensitive means is adapted to acquire a region of interest corresponding to at least a portion of said images, and wherein said means for transferring transfers a portion of said energy stored in said vertical register corresponding to a portion of said region of interest into said horizontal register, further comprising

enabling means for enabling transfer of said optical energy stored in said horizontal registers therefrom, and

disabling means for disabling transfer of optical energy from said vertical registers into said horizontal registers during said transfer of optical energy out of said horizontal registers.

21. A system according to claim 9, wherein said images have a region of interest corresponding to a portion of said images, said region of interest having a selected number of pixels, further comprising

pixel evaluation memory means coupled to image acquisition means for storing a value corresponding to said selected number of pixels, and

pre-determined pixel storage means coupled to said image acquisition means for storing a value corresponding to a predetermined number of pixels.

22. A system according to claim 21, further comprising

comparing means for comparing said value stored in said pixel evaluation means with said value stored in said pre-determined pixel storage means, and

means for generating a match signal when said values are equal, said programmable control means including means for receiving said match signal and for altering said image acquisition parameters.

23. A system according to claim 1, wherein said image acquisition means acquires said images in parallel with and substantially independently of allocation of memory by the host processor.

24. A system according to claim 1, wherein said images acquired by said image acquisition means includes a plurality of pixels, further comprising pixel correction means in circuit with said image acquisition means for correcting said pixels prior to transfer to said memory means.

25. A system according to claim 24, wherein said pixel correction means comprises

second memory means for storing a plurality of pre-determined pixel correction values corresponding to each pixel of said images, and

multiplier means for multiplying each pixel of said images by said corresponding pixel correction value, thereby forming a corrected pixel.

26. A system according to claim 24, wherein said pixel correction means is separate from the host processor and performs said pixel correction in real time.

27. A system according to claim 1, wherein said image acquisition means is capable of acquiring portions of two or more of said images based on a first set of image acquisition parameters for a first of said two or more images which may be different from a second set of image acquisition parameters for a second of the two or more images or based on at least two sets of image acquisition parameters which may have like parameters for two or more of said images.

28. A system for transmitting an image to a machine vision system having a host processor that allocates host memory locations for storage of an image acquired by said system, said system comprising:

image acquisition means for acquiring at least a portion of said image in response to a trigger signal from said machine vision system, said trigger signal providing said image acquisition means with a selected image parameter for said image; and

image transfer means for transferring said image from said image acquisition means to temporary memory, prior to transfer of said image to memory locations allocated by the host processor, said image transfer means including

transfer interruption means for interrupting transfer of said image to the temporary memory at an interruption point, and

transfer resumption means to resume transfer of said image to the temporary memory from said interruption point,

wherein said image acquisition means, in response to a transfer interruption by said transfer interruption means, holds portions of the image not yet received correctly by said temporary memory until instructed to restart transfer of said portions of said image to said temporary memory or said host memory locations.

29. An image acquisition system for connection to a machine vision system for acquiring an image of an object, said system having a host processor and a host memory manager and comprising:

image acquisition means for acquiring said image of the object, said image acquisition means including,

photo-sensitive means for acquiring said image in response to an acquisition signal containing selected image acquisition parameters,

programmable control means in circuit with said photo-sensitive means for receiving a loading signal and for programmatically altering prior to or during acquisition of said image said selected image acquisition parameters,

vertical memory means for storing at least a portion of said image, and

transfer means for transferring said image from said vertical memory means of said image acquisition means to a memory means in response to one or more release signals asserted by one or more components forming a portion of a data transmission path from the image acquisition means to the memory means.

30. The image acquisition system of claim 29, wherein said photo-sensitive means includes a CCD array and said programmable control means includes a programmable imager CCD controller.

31. The image acquisition system of claim 29, wherein said programmable control means comprises:

a controller adapted to be programmed with said selected image acquisition parameters and for generating an acquisition signal in response to said loading signal, and

parameter loading means coupled to said controller for generating said actuation signal and for receiving said image acquisition parameters.

32. The image acquisition system of claim 31, further comprising

triggering means for generating a trigger signal in response to an input command signal, said parameter loading means generating said loading signal in response to said trigger signal, and

parameter memory means for receiving and storing said image acquisition parameters from the host processor.

33. The image acquisition system of claim 29, wherein said programmable control means includes a programmable imager controller circuit, said controller circuit being adapted to be programmed with said image acquisition parameters.

34. The image acquisition system of claim 33, wherein said programmable imager controller circuit includes means for receiving said image acquisition parameters in less than or equal to about 2 μ

s.

35. The image acquisition system of claim 33, wherein said programmable imager controller circuit includes means for reprogramming said circuit on the fly, in essentially real time.

36. The image acquisition system of claim 33, wherein said programmable imager controller circuit operates at a driving frequency, said programmable imager controller circuit comprising means for automatically changing said driving frequency during acquisition of said image.

37. The image acquisition system of claim 29, wherein said image acquisition means further includes

triggering means for generating an output trigger signal in response to a command signal,

parameter memory means adapted for receiving said selected image acquisition parameters from the host processor, and

a camera loader circuit adapted to receive said selected image acquisition parameters from said parameter memory means and said output trigger signal, for programming said programmable control means with said image acquisition parameters.

38. The image acquisition system of claim 29, wherein said memory means comprises one or more vertical registers coupled to said photo-sensitive means for storing optical energy representative of said acquired image, and one or more horizontal registers positioned to receive at least a portion of said optical energy stored in said one or more vertical register.

39. The image acquisition system of claim 38, wherein said photo-sensitive means is adapted to acquire a region of interest corresponding to at least a portion of said image, further comprising

second means for transferring a portion of said optical energy corresponding to a portion of said region of interest from said one or more vertical registers to said one or more horizontal registers, and

disabling means for disabling transfer of optical energy from said one or more horizontal registers-during said transfer of optical energy from said one or more vertical registers into said one or more horizontal registers,

whereby said optical energy corresponding to a portion of said region of interest is rapidly transferred from said one or more vertical registers to said one or more horizontal registers without actively removing said transferred energy from said one or more horizontal registers.

40. The image acquisition system of claim 39, wherein said photo-sensitive means is adapted to acquire a region of interest corresponding to at least a portion of said image, further comprising

second means for transferring a portion of said energy stored in said vertical registers corresponding to a portion of said region of interest to said horizontal registers,

enabling means for enabling transfer of optical energy stored in said horizontal registers therefrom, and

disabling means for disabling transfer of optical energy from said vertical registers into said horizontal registers during said transfer of optical energy out of said horizontal registers.

41. The image acquisition system of claim 29, wherein said memory means comprises a data FIFO register, wherein said transfer means transfers said image into said register.

42. The image acquisition system of claim 41, further comprising second transfer means for transferring said image data accumulated in said data FIFO register to host memory of the system.

43. The image acquisition system of claim 42, wherein said second transfer means transfers data from said data FIFO register substantially independently of the host memory manager of the system.

44. The image acquisition system of claim 41, further comprising memory address transfer means for transferring said data stored in said data FIFO register directly to an address in host memory of the system, thereby substantially reducing the number of times the system interrupts the host processor.

45. The image acquisition system of claim 41, further comprising pre-processing means separate from the host processor for receiving said image data and for at least partially processing said data without interrupting said host processor.

46. The image acquisition system of claim 41, further comprising interrupt means coupled to said data FIFO register and to said image acquisition means for interrupting said acquisition of said images when said data FIFO register is full, thereby permitting reliable transfer of data corresponding to said image.

47. The image acquisition system of claim 46, wherein said interrupt means is capable of interrupting said acquisition of said images between lines corresponding to said images.

48. The image acquisition system of claim 46, wherein said interrupt means is adapted for immediately and temporarily interrupting said acquisition of said image.

49. The image acquisition system of claim 29, wherein the host processor allocates memory for storage of said image, and wherein said programmable control means generates said acquisition signal substantially independently of allocation of the memory by the host processor.

50. The image acquisition system of claim 29, wherein the host processor allocates memory for storage of said image, and wherein said programmable control means generates said acquisition signal in parallel with and substantially independently of allocation of the memory by the host processor.

51. The image acquisition system of claim 50, wherein said image acquired by said image acquisition means includes a plurality of pixels, further comprising pixel correction means in circuit with said image acquisition means for correcting said pixels prior to transfer to said memory means.

52. The image acquisition system of claim 51, wherein said pixel correction means is separate from one of the host processor and the host computing system and performs said pixel correction in real time.

53. The image acquisition system of claim 52, wherein a region of interest corresponding to a portion of said image includes a selected number of pixels, further comprising

pixel evaluation memory means coupled to image acquisition means for storing a value corresponding to said pixels of said region of interest, and

pre-determined pixel storage means coupled to said image acquisition means for storing a value corresponding to a predetermined number of pixels.

54. The image acquisition system of claim 50, wherein said pixel correction means comprises

second memory means for storing a plurality of pre-determined pixel correction values corresponding to each pixel of said image, and

multiplier means for multiplying each pixel of said image by said corresponding pixel correction value, thereby forming a corrected pixel.

55. The image acquisition system of claim 52, further comprising

comparing means for comparing said value stored in said pixel evaluation means with said value stored in said pre-determined pixel storage means, and

means for generating a match signal when said values are equal, said programmable control means including means for receiving said match signal and for altering said image acquisition parameters.