**3.5 CHAOS and clues**

A modified form of pattern analysis [45] looks for CHAOS (asymmetry of structure and/or color) and no less than one clue to diagnose malignancy. It can be


### **Table 4.**

*Total dermoscopic score of ABCD rule.*

*An Efficient Block-Based Algorithm for Hair Removal in Dermoscopic Images DOI: http://dx.doi.org/10.5772/intechopen.80024*


**Table 5.**

*Evaluation operation of BLINCK algorithm.*

connected to melanocytic and non-melanocytic lesions. Patterns are portrayed by different components of a similar sort: lines, dots, clods, circles, pseudopods (a line with a bulbous end), and structureless regions. Structureless zones are comprised of colors: black, dark brown, light brown, gray, blue, orange, yellow, white, red, and purple.


Asymmetrical patterns should prompt searching for particular clues to malignancy. The clues to malignancy are: thick reticular lines, gray or blue structures of any kind, pseudopods or radial lines at the periphery, black dots in the periphery, eccentric structureless area of any color, polymorphous vascular pattern, white lines, parallel lines on ridges, and large polygons.
