Method and system for visual change detection using multi-scale analysis
The disclosure herein generally relate to scene change detection, and, more particularly, to use of Unmanned Vehicle (UV) to inspect a scene and perform a scene change detection using UVs. When a UV performs visual inspection of an area or an object, due to various factors, such as but not limited to environmental factors, and movement of object and/or the UV, image of the area/object captured by the drone lacks clarity, which in turn makes detection of any object a difficult task. The UV disclosed herein uses a multi scale super pixel technique for visual change detection, in order to solve the aforementioned issues. In an embodiment, the UV captures an image, identifies a reference image that matches the captured image, and generates a change map. The multi-scale super pixel analysis is then performed on this change map to detect changes between the captured image and the reference image.
1. A processor-implemented method for change detection using an Unmanned Vehicle (UV), comprising:
capturing at least one image of a target, via one or more hardware processors;
identifying a reference image that matches the captured at least one image, from a plurality of reference images, via the one or more hardware processors;
generating a similarity map based on the captured at least one image and the reference image, via the one or more hardware processors, wherein the similarity map highlights changes between the captured at least one image and the reference image; and
extracting differences between the captured at least one image and the reference image, by performing a multi-scale super pixel analysis of the similarity map, via the one or more hardware processors, wherein performing the multi-scale super pixel analysis of the similarity map comprises of:
computing a Gaussian pyramid of the captured at least one image and corresponding reference image, at a plurality of different scales;
generating super pixels for the at least one captured image, at each of the plurality of different scales;
generating a super-pixel based change map, at each of the plurality of different scales, to obtain a set of super-pixel based change maps;
generating a combined change map, based on the set of super-pixel based change maps; and
identifying overlapping regions in the combined change map.
2. The method as claimed in claim 1 , wherein the reference image that matches the captured at least one image is identified by performing frame matching of the captured at least one image with each of said plurality of reference images.
3. The method as claimed in claim 1 , wherein generating the similarity map comprises of:
computing structural similarity values between the captured at least one image with each of said plurality of reference images at pixel level; and
generating the similarity map, based on the computed structural similarity values.
4. An Unmanned Vehicle (UV), comprising:
a processor; and
a memory module comprising a plurality of instructions, said plurality of instructions configured to cause the processor to:
capture at least one image of a target, via one or more hardware processors, by an image capturing module of the UV;
identify a reference image that matches the captured at least one image, from a plurality of reference images, via the one or more hardware processors, by an image processing module of the UV;
generate a similarity map based on the captured at least one image and the reference image, via the one or more hardware processors, by the image processing module, wherein the similarity map highlights changes between the captured at least one image and the reference image; and
extract differences between the captured at least one image and the reference image, by performing a multi-scale super pixel analysis of the similarity map, via the one or more hardware processors, by the image processing module, wherein the image processing module is configured to perform the multi-scale super pixel analysis of the similarity map by:
computing a Gaussian pyramid of the captured at least one image and corresponding reference image, at a plurality of different scales;
generating super pixels for the at least one captured image, at each of the plurality of different scales;
generating a super-pixel based change map, at each of the plurality of different scales, to obtain a set of super-pixel based change maps;
generating a combined change map, based on the set of super-pixel based change maps; and
identifying overlapping regions in the combined change map.
5. The UV as claimed in claim 4 , wherein the image processing module is configured to identify the reference image that matches the captured at least one image, by performing frame matching of the captured at least one image with each of said plurality of reference images.
6. The UV as claimed in claim 4 , wherein the image processing module is configured to generate the similarity map by:
computing structural similarity values between the captured at least one image with each of said plurality of reference images at pixel level; and
generating the similarity map, based on the computed structural similarity values.
7. One or more non-transitory machine readable information storage mediums comprising one or more instructions which when executed by one or more hardware processors causes:
capturing at least one image of a target, via one or more hardware processors;
identifying a reference image that matches the captured at least one image, from a plurality of reference images, via the one or more hardware processors;
generating a similarity map based on the captured at least one image and the reference image, via the one or more hardware processors, wherein the similarity map highlights changes between the captured at least one image and the reference image; and
extracting differences between the captured at least one image and the reference image, by performing a multi-scale super pixel analysis of the similarity map, via the one or more hardware processors, wherein the multi-scale super pixel analysis of the similarity map, comprising:
computing a Gaussian pyramid of the captured at least one image and corresponding reference image, at a plurality of different scales;
generating super pixels for the at least one captured image, at each of the plurality of different scales;
generating a super-pixel based change map, at each of the plurality of different scales, to obtain a set of super-pixel based change maps;
generating a combined change map, based on the set of super-pixel based change maps; and
identifying overlapping regions in the combined change map.
8. The one or more non-transitory machine readable information storage mediums of claim 7 , wherein the one or more instructions which when executed by the one or more hardware processors cause identification of the reference image that matches the captured at least one image by performing frame matching of the captured at least one image with each of said plurality of reference images.
9. The one or more non-transitory machine readable information storage mediums of claim 7 , wherein the one or more instructions which when executed by the one or more hardware processors cause generation of the similarity map by:
computing structural similarity values between the captured at least one image with each of said plurality of reference images at pixel level; and
generating the similarity map, based on the computed structural similarity values.