Chakraborty, Biplab Ketan2020-03-042023-10-202020-03-042023-10-202018ROLL NO.126102023https://gyan.iitg.ac.in/handle/123456789/1412Supervisor: M.K. BhuyanSkin detection is an important step in various image processing and vision-based Human-Computer Interaction (HCI) applications. It is the process of finding skin-coloured pixels and regions in an image or a video. The major challenges of skin detection in images are -- presence of skin-like colours in background and changes in chromatic appearance of skin regions due to non-uniform illumination. In addition to these problems, detection of skin regions in videos is more challenging in presence of time-varying illumination conditions and dynamic backgrounds. Motivated by these facts, we have proposed a set of skin detection algorithms for different environmental conditions using chromatic and textural properties of skin regions. A new probability map termed as discriminative space map (DSM) is proposed by extracting most discriminative features between skin and non-skin regions. A novel adaptive discriminative analysis (ADA) is proposed to extract most discriminant features between skin and non-skin regions from an image itself in an unsupervised manner. Subsequently, a dynamic region growing (DRG) method is employed to allow skin regions to grow dynamically. To handle effect of non-uniform illumination on skin colour, a novel skin detection method is proposed by utilising an image pixel distribution model (IDM), which is derived using a Gaussian Mixture Model (GMM) in a given colour space. In this method, a local skin distribution model (LSDM) and a local background distribution model (LBDM) are derived by exploiting the similarity between the IDM and a reference skin pixel distribution model. The reference skin model is derived from a set of facial skin pixels, and it is termed as facial skin distribution model (FSDM). A local skin probability map (LSPM) can be derived using the LSDM and the LBDM.enELECTRONICS AND ELECTRICAL ENGINEERINGThesis