WEEK 8: WEB-ASSISTED OBJECT DETECTION ALEJANDRO TORROELLA & AMIR R. ZAMIR.

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WEEK 8:

WEB-ASSISTED OBJECT

DETECTION

A L E J A N D R O TO R R O E L L A &

I R R . ZA M

GEOMETRY METHOD PROCEDURE

For each query image we manually set orientation, angle of view, range of view, and location of camera.

: Camera location

: Object locations

: Field of vision

GEOMETRY METHOD PROCEDUREUsing the obtained FOV, select only the objects that are within the

Calculate the degrees from the left limit of the FOV and store in a vector specific to the object’s class These vectors will be

our “true” layout of objects.

GEOMETRY METHOD PROCEDUREWe then run our DPM detectors for the classes in question on the

query image.

Below are results for Street Lights (green) and Traffic Signals (red).

GEOMETRY METHOD PROCEDUREWe sift through the detections that completely disagree with the

“true” GIS layout.

GEOMETRY METHOD PROCEDUREWe then sift through the detections again by size of bounding boxes

(too large or too small)

GEOMETRY METHOD PROCEDUREUsing the sifted bounding boxes we generate all possible

combinations (no repeats, order doesn’t matter) of possible layouts.

For each class: Out of the N detections, choose k of them for the possible layout. Where

For each layout combination we calculate the “cost” of it compared to the obtained “true” GIS layout and keep track of the combination that returned the minimum

Two cost functions we’ve tested:

Absolute value:

Standard deviation:

GEOMETRY METHOD PROCEDUREOnce we’ve traversed through all the possible combinations, we

display the detections that resulted in the minimum of the cost function.

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GEOMETRY METHOD RESULTS: BEFORE

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Traffic SignalsTrash CansTraffic Signs

GEOMETRY METHOD RESULTS: AFTER GIS SIFT

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GEOMETRY METHOD RESULTS: AFTER SIZE SIFT

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GEOMETRY METHOD RESULTS: AFTER FUSION (ABS)

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GEOMETRY METHOD RESULTS: AFTER FUSION (STD)

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Traffic SignalsStreet Lights

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Street LightsTraffic Signs

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Fire HydrantsStreet Lights

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Traffic SignalsTraffic Signs

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GEOMETRY METHOD CONCLUSIONS

• Using the Standard deviation cost function resulted in better results compared to the Absolute value function on average.• A more advanced cost function would probably result in

even better results• Results look promising considering we haven’t implemented a

robust sensor model for creating the “true” GIS layout

GOALS FOR NEXT WEEK

• Implement a robust sensor model• Look into more advanced cost functions• Instead of crudely sifting through the bounding boxes by size

using a threshold based on the size of the image, use the distances of the objects from the camera to estimate how large the bounding box should be.

THANK YOUFIN.

WEEK 8: WEB-ASSISTED OBJECT DETECTION ALEJANDRO TORROELLA & AMIR R. ZAMIR.

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