Reconfigurable video line digitizer and method for storing predetermined lines of a composite video signal

• US 5,034,817 A
• Filed: 02/28/1990
• Issued: 07/23/1991
• Est. Priority Date: 02/28/1990
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Everett, Hobart R. Jr.
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US07/486,465
• Time in Patent Office: 510 Days
• Field of Search: 358/107, 358/126, 358/160
• US Class Current: 348/571
• CPC Class Codes: H04N 5/14 Picture signal circuitry for video frequency region cameras or camera modules comprising electronic image sensors, or control thereof H04N23/00

Abstract

A video line digitizer for digitizing predetermined lines of successive fes of a composite video signal includes a video line digitizer for converting the analog component of the video signal into a series of digital data representations. The composite video signal consists of successive frames. The frames each consist of a fixed number of lines represented by a fixed number of pixels. The pixels each have an associated intensity value reflected in the resulting digital data representations. The video line digitizer also provides synchronization signals decoded from the composite video signal to an address decoder/controller which determines the beginning of each horizontal line of the image. A high-speed RAM receives the digital data representations from the video line digitizer and stores them in address locations provided to the RAM by the address decoder/controller when the RAM is enabled by a data processor. The data processor receives the sync signals from the video line digitzer in order to identify the end of the designated line of interest. The data processor then disables the RAM from receiving additional data and directs the RAM to download the stored data into another RAM in the processor, from which the processor later retrieves the data for subsequent analysis.

Claims

1. A video line digitizer, comprising:

first means having a composite video signal input for converting a composite video signal having an analog component into a series of digital data representations of said analog component, said composite video signal consisting of successive frames, each frame consisting of a fixed number of lines, each line having a fixed number of pixels, each pixel having an associated intensity, and for providing synchronization signals decoded from said video signal, said series of digital data representations corresponding to said intensities of said pixels of said lines;

second means, operably coupled to receive said series of digital data representation from said first means, for storing a subset of said series of digital data representations corresponding to a predetermined line of a frame of said video signal in a memory, said subset comprising subset data;

third means operably coupled to receive said synchronization signals from said first means and operably coupled to said second means for directing said second means to sequentially store said subset in said memory upon receipt by said second means of an address signal, said third means having an address input; and

fourth means operably coupled to receive said synchronization signal from said first means and said subset data from said second means, and having an address output operably coupled to provide said address signal to said address input of said third means, for causing said second means to download said subset to said fourth means.

2. The video line digitizer of claim 1 wherein said first means comprises:

a sync stripper having said composite video signal input for decoding said composite video signal and for providing a horizontal sync output, a vertical sync output, and a pixel clock output; and

a flash analog-to-digital converter having said composite video signal input and a data output for converting said analog component of said composite video signal into said series of digital data representations.

3. The video line digitizer of claim 2 wherein:

said fourth means is a digital data processor having a random access memory, an end-of-line input, horizontal and vertical sync inputs operably coupled to receive said horizontal and vertical sync outputs, respectively, from said sync stripper, an address output, a data bus output, and first and second "change state" outputs; and

said third means comprises;

a flip-flop having a horizontal sync input operably coupled to said horizontal sync output of said sync stripper, and a delay counter control output;

a delay counter having a first input operably coupled to said delay counter control output of said flip-flop, a second input operably coupled to said pixel clock output of said sync stripper, and an output;

a dip switch programmed to have a predetermined delay operably coupled to said delay counter for delaying the output of said delay counter until said delay counter has counted a predetermined number of pixel counts corresponding to said delay, said predetermined number of pixel counts corresponding to the beginning of said analog component of said composite video signal;

a pixel counter having a pixel clock input operably coupled to said pixel clock output of said sync stripper, a delay counter input operably coupled to said output of said delay counter for inhibiting operation of said pixel counter for a predetermined number of clock pulses, an address output operably coupled to said second means for providing address locations in said second means in which said subset data are stored, and an end-of-line counter output operably coupled to said end-of-line input of said digital data processor; and

an address decoder having an address input operably coupled to said address output of said digital data processor, a first address output for providing a first address signal to said random access memory of said digital data processor, and a second address output for providing said second address output to said second means.

5. The video line digitizer of claim 1 wherein:

said first means comprises;

a sync stripper having said composite video signal input for decoding said composite video signal and for providing a horizontal sync output, a vertical sync output, and a pixel clock output; and

a flash analog-to-digital converter having said composite video signal input and a data output for converting said analog component of said composite video signal into said series of digital data representations;

said fourth means is a digital data processor having a random access memory, an end-of-line input, horizontal and vertical sync inputs operably coupled to receive said horizontal and vertical sync outputs, respectively, from said sync stripper, an address output, a data bus output, and first and second "change state" outputs, and a data link;

said third means comprises;

a flip-flop having a horizontal sync input operably coupled to said horizontal sync output of said sync stripper, and a delay counter control output;

a delay counter having a first input operably coupled to said delay counter control output of said flip-flop, a second input operably coupled to said pixel clock output of said sync stripper, and an output;

a dip switch operably coupled to said delay counter for delaying the output of said delay counter until said delay counter has counted a predetermined number of pixel counts, said predetermined number of pixel counts corresponding to the beginning of said analog component of said composite video signal;

a pixel counter having a pixel clock input operably coupled to said pixel clock output of said sync stripper, a delay counter input operably coupled to said output of said delay counter for inhibiting operation of said pixel counter for a predetermined number of clock pulses, an address output operably coupled to said second means for providing address locations in said second means in which said subset data are stored, and an end-of-line counter output operably coupled to said end-of-line input of said digital data processor; and

an address decoder having an address input operably coupled to said address output of said digital data processor, a first address output for providing a first address signal to said random access memory of said digital data processor, and a second address output for providing said second address output to said second means; and

said second means comprises;

a first buffer having a data input operably coupled to said data output of said analog-to-digital converter, a "change state" input operably coupled to said first "change state" output from said digital data processor, and a data output for providing said subset data;

a second buffer having an address input operably coupled to said address output of said pixel counter, a "change state" input operably coupled to said first "change state" output of said digital data processor, and an address output;

a random access memory having a data input operably coupled to receive said subset data from said data output of said first buffer, an address input operably coupled to said address output of said second buffer, and a data output;

a third buffer having a data input operably coupled to said data output of said random access memory, a "change state" input operably coupled to said second "change state" output of said digital data processor, and a data output operably coupled to said digital data processor; and

a fourth buffer having an address input operably coupled to said second address output of said decoder, a "change state" input operably coupled to second "change state" output of said digital data processor, and an address output operably coupled to provide said address input of said random access memory.

6. The video line digitizer of claim 5 wherein:

said digital data processor identifies said subset data corresponding to said pixels having intensity values corresponding to a predetermined attribute.

7. The video line digitizer of claim 6 which further includes:

a video camera having a composite video signal output operably coupled to said composite video signal inputs of said sync stripper and flash analog-to-digital converter.

8. The video line digitizer of claim 5 wherein:

said digital data processor compares said subset data corresponding to a predetermined line of a first frame of said composite video signal to said subset data corresponding to said predetermined line of a second frame of said composite video signal.

9. The video line digitizer of claim 8 which further includes:

a video camera having a composite video signal output operably coupled to said composite video signal inputs of said sync stripper and flash analog-to-digital converter.

10. The video line digitizer of claim 5 wherein:

said digital data processor compares said subset data corresponding to a plurality of predetermined lines of a first frame of said composite video signal to said subset data corresponding to said plurality of predetermined line of a second frame of said composite video signal and provides an output functionally related to said comparisons.

11. The video line digitizer of claim 10 which further includes:

a video camera having a composite video signal output operably coupled to said composite video signal inputs of said sync stripper and flash analog-to-digital converter.

12. The video line digitizer of claim 5 wherein:

said digital data processor determines which of said lines of said composite video signal are to be stored in said random access memory based on the outcomes of mathematical analyses performed by said digital data processor on said subset data.

13. The video line digitizer of claim 12 which further includes:

a video camera having a composite video signal output operably coupled to said composite video signal inputs of said sync stripper and flash analog-to-digital converter.

14. The video line digitizer of claim 1 wherein:

said digital data processor compares said subset data corresponding to a predetermined line of a first frame of said composite video signal to said subset data corresponding to said predetermined line of a second frame of said composite video signal.

15. The video line digitizer of claim 1 wherein:

said digital data processor compares said subset data corresponding to a plurality of predetermined lines of a first frame of said composite video signal to said subset data corresponding to said plurality of predetermined line of a second frame of said composite video signal and provides an output functionally related to said comparisons.

16. The video line digitizer of claim 1 wherein:

said digital data processor determines which of said lines of said composite video signal are to be stored in said memory based on the outcomes of mathematical analyses performed by said digital data processor on said subset data.

4. The video line digitizer of 3 wherein:

said second means comprises;

a first buffer having a data input operably coupled to said data output of said analog-to-digital converter, a "change state" input operably coupled to said first "change state" output from said digital data processor, and a data output for providing said subset data;

a second buffer having an address input operably coupled to said address output of said pixel counter, a "change state" input operably coupled to said first "change state" output of said digital data processor, and an address output;

a random access memory having a data input operably coupled to receive said subset data from said data output of said first buffer, an address input operably coupled to said address output of said second buffer, and a data output;

a third buffer having a data input operably coupled to said data output of said random access memory, a "change state" input operably coupled to said second "change state" output of said digital data processor, and a data output operably coupled to said digital data processor; and

a fourth buffer having an address input operably coupled to said address output of said output address decoder, a "change state" input operably coupled to said second "change state" output of said digital data processor, and an address output operably coupled to provide said address input of said random access memory.

17. A method for storing and comparing predetermined lines of a composite video signal, comprising the steps of:

converting a composite video signal having an analog component into a series of digital data representations of said composite video signal, said video signal consisting of successive frames, each frame consisting of a fixed number of lines, each line represented by a fixed number of pixels, each pixel having an associated intensity, said digital data representations corresponding to said intensities of said pixels of said lines;

storing each of said series of digital data representations corresponding to a predetermined line of said composite video signal in a memory; and

identifying data included within said digital data representations, said data corresponding to said pixels having intensity values corresponding to a predetermined attribute.

18. A method for storing and comparing predetermined scan lines of a composite video signal, comprising the steps of:

converting a composite video signal having an analog component into a series of digital data representations of said composite video signal, said video signal consisting of successive frames, each frame consisting of a fixed number of scan lines, each said scan line represented by a fixed number of pixels, each pixel having an associated intensity, said digital data representations corresponding to said intensities of said pixels of said scan lines;

storing each of said series of digital data representations corresponding to a first predetermined scan line of said composite video signal in a random access memory; and

identifying an updated set of said digital data representations which are to be stored in said random access memory based on the outcomes of mathematical analyses performed by a digital data processor on said series of digital data representations which were previously stored.

19. A method for comparing scan lines of a composite video signal, comprising the steps of:

a) converting a composite video signal having an analog component into a series of digital data representations of said composite video signal, said video signal consisting of successive frames, each frame consisting of a fixed number of said scan lines, each said scan line represented by a fixed number of pixels, each pixel having an associated intensity, said digital data representations corresponding to said intensities of said pixels of said scan lines;

b) storing an mth series of said digital data representations, corresponding to an mth set of said scan lines, in a memory, said mth set comprising at least one predetermined scan line, where m is a positive integer;

c) identifying an (m+1)th series of said digital data representations, corresponding to an (m+1)th set of said scan lines comprising at least one of said scan lines, based on the outcomes of mathematical analyses performed by a digital data processor on said mth series of digital data representations;

d) storing said (m+1)th series of digital representations in said memory; and

e) repeating steps (a) through (d) an n number of times, where n is a positive integer.