Linked Questions

1
vote
0answers
71 views

How does Image Search on Google + work [duplicate]

I found out today about Google +'s image search feature. It allows users to perform a text-based search for objects within their picture library. I was instantly curious to know how this feature works....
65
votes
4answers
48k views

What are some free alternatives to SIFT/ SURF that can be used in commercial applications?

As far as I understand, both SURF and SIFT are patent protected. Are there any alternative methods that can be used in a commercial application freely? For more info on the patent check out: http://...
15
votes
4answers
4k views

List of possible image features for content based image retrieval

I am trying to find a list of possible image features like color, oriented edges and so on for measuring their usability in case of finding same/similar objects in images. Does anyone know such a list ...
16
votes
5answers
16k views

Scale and Rotation invariant feature descriptors

Can you list some scale and rotational invariant feature descriptors for use in feature detection. The application is for the detection of cars and humans in video captured by a UAV, using a multi-...
16
votes
2answers
19k views

Why do we use keypoint descriptors?

I just studied about SURF and I'm going for its implementation, but I still didn't understand why we use descriptors. I understand what keypoints are and their purpose, but when we extract the ...
13
votes
3answers
4k views

Is sift a good way to extract features from an image?

I am trying to extract features from an image, but I have failed to get the points that I want to extract, and hence my image fails to match with the template. Are there any checkpoints that I have ...
8
votes
2answers
5k views

What is the Compression Algorithm used by Facebook?

I would like to know what is the Compression Algorithm used by Facebook for compressing the images? I uploaded a image of size 242 Kb and I downloaded the same image from my Facebook album. The size ...
14
votes
1answer
5k views

What distance metric can I use for comparing images?

I usually use the mean squared error (MSE) or peak signal-to-noise ratio (PSNR) to compare two images, but this isn't good enough. I need to find a formula that returns a very big distance between an ...
14
votes
2answers
1k views

Image Registration by Segmentation

Image registration algorithms are usually based on point features such as SIFT (Scale-Invariant Feature Transform). I saw some references to line features, but I was wondering if it would be possible ...
10
votes
2answers
886 views

Segmentation of half transparent material, e.g. glass

I'm totally stuck on an issue regarding the segmentation of glassy objects. I need to get the object as precise as possible. My approaches were different. At first I tried to remove the background, so ...
2
votes
2answers
190 views

Is there an algorithm to compare several pictures?

I'm looking for an algorithm to store small dimensions of some pictures and later search on the stored data for matches similar to a new picture. Maybe something with Self Organizing Map in machine ...
4
votes
0answers
479 views

How to construct descriptors for irregularly shaped image patches

As hinted in this answer, Perceptual hashing is a way to ascribe comparable measures (hashes) to images (rectangular patches). The images do not need to be the same size, and can be slightly distorted,...
0
votes
1answer
180 views

Can anyone suggest good algorithms for CBIR?

Project: Content Based Image Retrieval - Semi-supervised (manual tagging is done on images while training) Description I have 1000000 images in the database. The training is manual (supervised) - ...