Thursday, 19 November 2009

Face Sketching

This material actually is my slides presentation when being requested to be instructor on Frontline Forensic Course in Indonesia. This course has been being conducted since 16 November till 4 December 2009. In this course, I deliver teaching materials about Digital Forensic, Face Sketching, Photography Forensic, Fire Investigation and GPS. In this post, I just describe my materials on Face Sketching. The full version of this material can be downloaded at this link

Face sketching is required when criminal investigators would like to obtain description of somebody based on the witness testimony. It is performed in order to have suspect's face so that it is easy to recognise by the investigators, even public can know him when seeing him anytime and anywhere. To reach this condition, the results of face sketching are distributed not only for law enforcement agencies but also for public. When people see the suspect, they will contact law enforcement agency to inform his existence; and then the investigators could arrest him soon.

However, there are also problems encountering the process of face sketching, such as:
1. Witnesses might saw the suspect at glance, so that it is not enough to identify him perfectly as the witness can not give face components in details.
2. Witnesses might saw the suspect from behind and or from right/left side, so that the description of suspect's face is not sufficient to describe.
3. The limits of memory of the witnesses. It means that when a witness saw the suspect, it does not guarantee he could recognise the suspect's face in details. There is possibility that the face description will be distorted as the witness can not remember each face components in details.
4. The lack of lights. When a witness saw the suspect in the condition of dark situation (i.e a little light), he can not describe the suspect's face perfectly as he can not see it well.

In the process of face sketching, there are two components which chould be considered, namely:
1. General characteristics
2. Class characteristics

In General characteristics, it shows a general pattern of a face component such as:
1. Eyes
2. Noses
3. Eyebrows
4. Hair
5. Lips
6. Head shapes
7. Jaw shapes
8. Mustaches
9. Beards
10. Eye lines
11. Smile lines

Meanwhile, in class characteristics, it shows a specific pattern of a component and or a specific sign on a face such as:
1. Mole or beauty spot
2. Cockeye or a cast in the eye
3. Harelip
4. Scar or wound print

The techniques developed in the process of face sketching are:
1. Manual. It requires a good painter

2. Automatic. It requires a reliable computer application

To obtain the description of face sketching in details, please click the link above. Hopefully it could be useful for anybody who would like to explore face recognition. Good luck...!

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