Non-maximum suppression in image data
An apparatus includes a first circuit, a second circuit and a third circuit. The first circuit may be configured to set a flag where a current value in a current line of an image is a maximum value in a first window in the current line. The second circuit may be configured to reset the flag based on one or more previous lines of the image where the current value is not a largest value in a second window around the current value. The third circuit may be configured to generate an output value as (i) the current value if the flag is set and (ii) a predetermined value if the flag is reset.
1. An apparatus comprising:
a first circuit configured to set a flag where a current value in a current line of an image is a maximum value in a first window in said current line;
a second circuit configured to reset said flag based on one or more previous lines of said image where said current value is not a largest value in a second window around said current value; and
a third circuit configured to generate an output value as (i) said current value if said flag is set and (ii) a predetermined value if said flag is reset.
2. The apparatus according to claim 1 , further comprising a fourth circuit configured to buffer said current value and said flag, wherein said third circuit is further configured to (i) receive said flag from said fourth circuit and (ii) reset said flag based on one or more next lines of said image where said current value is not said largest value in said second window around said current value.
3. The apparatus according to claim 1 , further comprising a fourth circuit configured to buffer at most a ceiling of one half of said second window at all times.
4. The apparatus according to claim 1 , further comprising a fifth circuit configured to (i) buffer at least two lines of said image and (ii) process said image using a two-dimensional extent.
5. The apparatus according to claim 4 , wherein said fifth circuit is further configured to (i) generate a plurality of additional flags that identify where a greatest value is located in said two-dimensional extent, and (ii) transfer said additional flags to said first circuit.
6. The apparatus according to claim 5 , wherein resetting of said flag in said second circuit is further based on said additional flags.
7. The apparatus according to claim 5 , wherein said third circuit is further configured to reset said flag based on one or more next lines of said image and said additional flags where said current value is not said largest value in said second window around said current value.
8. The apparatus according to claim 4 , further comprising a fourth circuit configured to buffer at most a ceiling of one half of said second window minus one at all times.
9. The apparatus according to claim 1 , wherein said apparatus forms part of a computer vision system.
10. The apparatus according to claim 1 , wherein said apparatus forms part of a digital camera.
11. A method for non-maximum suppression in image data, comprising the steps of:
setting a flag with a circuit where a current value in a current line of an image is a maximum value in a first window in said current line;
resetting said flag based on one or more previous lines of said image where said current value is not a largest value in a second window around said current value; and
generating an output value as (i) said current value if said flag is set and (ii) a predetermined value if said flag is reset.
12. The method according to claim 11 , further comprising the steps of:
buffering said current value and said flag in a line buffer; and
resetting said flag based on one or more next lines of said image where said current value is not said largest value in said second window around said current value.
13. The method according to claim 11 , further comprising the step of:
buffering at most one half rounded up of said second window at all times.
14. The method according to claim 11 , further comprising the steps of:
buffering at least two lines of said image; and
processing said image using a two-dimensional extent.
15. The method according to claim 14 , further comprising the steps of:
generating a plurality of additional flags that identify where a greatest value is located in said two-dimensional extent; and
transferring said additional flags to said circuit.
16. The method according to claim 15 , wherein resetting of said flag is further based on said additional flags.
17. The method according to claim 15 , further comprising the step of:
resetting said flag based on one or more next lines of said image and said additional flags where said current value is not said largest value in said second window around said current value.
18. The method according to claim 14 , further comprising the step of:
buffering at most a ceiling of one half of said second window minus one at all times.
19. The method according to claim 11 , wherein the steps are implemented in one or more of (i) a computer vision system, (ii) a digital camera or (iii) any combination thereof.
20. The method according to claim 11 , wherein the second window has fewer columns than said image.