Mar 13, 2011

Stranded turtles on Teknaf beach

Some stranded turtles were spotted on Teknaf beach during my last expedition to the area on 3rd March 2011.

Mar 10, 2011

Fiddler Crab Handedness Detection

Fiddler Crab is the common name for the semi-terrestrial crabs of the genus Uca. The males have an oversized claw or cheliped. If the large fiddle claw is lost, males will develop one on the opposite side after their next molt.

I recently stumbled upon a solution for determining handedness of a male fiddler crab from its photograph.

The procedure assumes that the photo shows front side of the crab and the fiddle claw is horizontal or nearly horizontal in the photo. The basic idea is to find out the fiddle claw and the hole formed between two pincers of the claw. From determining the center of mass of these two regions on the 2D image, it can be detected whether the crab is left-handed or right-handed.

The photo was shot last year during an expedition near the mangrove area of Reju Khal in Cox's Bazar.

Mar 7, 2011

Generation of Mountain Ranges by Modifying a Controlled Terrain Generation Approach

A modification and extension of the parametrically controlled terrain generation approach produces mountain ranges of predefined shape with peaks at specified coordinates.

Like the original algorithm, the parameters can be tweaked to generate craters instead of peaks and other interesting geographical features.

The work was published in ICCIT 2008, Khulna bearing title Generation of Mountain Ranges by Modifying a Controlled Terrain Generation Approach

Automatic Species ID : Lepidochelys olivacea

The automatic species ID procedure I'm working on, follows these steps of image manipulation and decision making to detect Lepidochelys olivacea from a photo. For demonstration I'm using an image contributed by M.A. Hannan.

1. Convert RGB image to Lab color space
2. Enhance 'b' channel of the image

3. Complement 'b' channel of the image

4. Threshold complemented 'b' channel of the image with a predefined constant, 210 for this image

5. Dilate the resulting image

6. Fill the resulting image

7. Erode the resulting image

8. Mark the blob with maximum area

9. If area of the marked blob is not less than 30% of the image size then declare detection of LO