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mitemitreski / javasurf

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Unrelevant features are detected #1

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
On any image I apply the library to, features appear in the lower right corner 
in a stationnary position

What steps will reproduce the problem?
1. take a pure white 512*512 png image
2.  threshold = 2000;
    balanceValue = 0.9;
    octaves = 8;
3. Run the algorithm/test suite against this image

The lower right corner contains irrelevant features, they are present even on 
non white images. (And if there is pattern, they don't move relative to the 
image even if the pattern rotates). This makes it very annoying when using the 
library to match and overlay 2 similar images.

The number of those detections increase with the number of octaves.

What version of the product are you using? On what operating system?

Please provide any additional information below.

Original issue reported on code.google.com by vincent....@gmail.com on 25 Jun 2010 at 8:00

Attachments:

GoogleCodeExporter commented 9 years ago 
What version of the product are you using? On what operating system?

I'm using svn revision 4 under Windows XP, jre1.6.0_07 & jdk1.6.0_07

Original comment by vincent....@gmail.com on 25 Jun 2010 at 8:02

GoogleCodeExporter commented 9 years ago

Original comment by vincent....@gmail.com on 25 Jun 2010 at 8:04

Attachments:

GoogleCodeExporter commented 9 years ago 
I am seeing these false artifacts as well. Any ideas why this would happen?

Original comment by peter.st...@gmail.com on 29 Sep 2010 at 12:14

GoogleCodeExporter commented 9 years ago 
The same problem occured under mac os 10.6 with jdk 1.6.
in the constructor of IntegralImage I found this:

            for (int i = 0; i < height - 1; i++) {
                float sumOfTheCurrentRow = 0;
                for (int j = 0; j < width - 1; j++) {

this is the problem, the last row and column stay filled with zeros, in 
different resolutions it is a very dominant feature and creates false interest 
points. Just delete the -1 or put a = behind the <.

Original comment by hpri...@gmail.com on 5 Apr 2011 at 1:05

Attachments:

GoogleCodeExporter commented 9 years ago 
Removing the -1 effectively gives more relevant features

Thanks

Original comment by yves.cui...@gmail.com on 30 Apr 2011 at 5:14