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Facial recognition
Facial recognition In late 1976, at about the same time as the first computer-generated colour pictures were displayed on Bugstore, the Police Scientific Development Branch of the Home Office, (PSDB), were seeking a computer system for the generation of facial images to aid the police in the identification of suspects. Because of its experience in the field of computer graphics, the CAD Centre was selected to work with the PSDB and psychologists from Aberdeen University on this challenging project. The equipment to be used was the Centre's newly developed Advanced Graphics Display Terminal (AGDTBugstore) driven by a Prime 300 minicomputer; the system would be built on the Centre's proprietory graphics software.
high-precision TV that displays messages • a keyboard through which the operator may give commands to the system • a tablet on which are displayed menus of commands. The operator drives the system by pointing to the relevant command within a menu with a proble (cursor)
•
a
System d~dption
• the minicomputer, which performs the complex image manipulation routines and controls the operation of the peripheral devices • a disc unit, which holds a library of the facial features, e.g. hair lines, eyes, noses, chins, etc., that the operator requires • the AGDT, which stores the picture data and continuously refreshes a TV screen (the picture is modified by sending new data from the computer to the AGDT)
Each program in the system is completely independent of the others. The 'generator' allows the user to extract facial features and store them in a library; the 'synthesiser' allows the user to retrieve features from the library and to build them up into a new face. A face may be considered as a composite of various facial features or areas which have to be matched by a series of selections and modifications of the stored records. For instance the face may be considered as a combination of hair, eyes, nose, mouth, chin, ears and other areas where lines or wrinkles may appear. Data are selected for each of these areas and a composite of the selected data is displayed on the TV screen. The data are then manipulated for each facial feature or area in turn until the image displayed becomes a good likeness of the person concerned, as far as can be judged from the recollections of witnesses or by comparison with available photographs. Controls are provided for adjusting the
Figure 1. Original likeness
Figure 2. Chenged mouth and nose
The equipment consists of:
volume 11 number 3 may 1979
boundaries of facial areas. In the neighbourhood of such boundaries, the display is derived from a mixture or combination of, or an interpolation between, details from different data relating to the features. The data used to generate the image on the T V screen are updated in AGDT after each modification, and the T V screen is continuously refreshed from the store within AGDT. Earlier systems for constructing a pictorial representation of a human face comprise an arrangement for making a combination of drawings or photographs of facial features selected from a kit. The quality of the representation achieved is limited by the fixed combinations of details appearing on the available drawings or photographs in the kit, and by the mismatches in tones or shading and gaps that tend to occur at the edges of the drawings or photographs combined together. The system developed at the CAD Centre allows more convenient, accurate and flexible adjustment of the representations formed. Figures 1 - 3 are photographs taken from the TV screen. Figure 1 is a television picture of a genuine person and the others are composites. The changes that have been made to arrive at this series can easily be traced. From Figure 1, changes to the mouth and nose produced Figure 2, then changes to the eyes and hair oroduced Figure 3.
Figure 3. Changed mouth, nose, eyes and hair
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high-precision TV that displays messages • a keyboard through which the operator may give commands to the system • a tablet on which are displayed menus of commands. The operator drives the system by pointing to the relevant command within a menu with a proble (cursor)
•
a
System d~dption
• the minicomputer, which performs the complex image manipulation routines and controls the operation of the peripheral devices • a disc unit, which holds a library of the facial features, e.g. hair lines, eyes, noses, chins, etc., that the operator requires • the AGDT, which stores the picture data and continuously refreshes a TV screen (the picture is modified by sending new data from the computer to the AGDT)
Each program in the system is completely independent of the others. The 'generator' allows the user to extract facial features and store them in a library; the 'synthesiser' allows the user to retrieve features from the library and to build them up into a new face. A face may be considered as a composite of various facial features or areas which have to be matched by a series of selections and modifications of the stored records. For instance the face may be considered as a combination of hair, eyes, nose, mouth, chin, ears and other areas where lines or wrinkles may appear. Data are selected for each of these areas and a composite of the selected data is displayed on the TV screen. The data are then manipulated for each facial feature or area in turn until the image displayed becomes a good likeness of the person concerned, as far as can be judged from the recollections of witnesses or by comparison with available photographs. Controls are provided for adjusting the
Figure 1. Original likeness
Figure 2. Chenged mouth and nose
The equipment consists of:
volume 11 number 3 may 1979
boundaries of facial areas. In the neighbourhood of such boundaries, the display is derived from a mixture or combination of, or an interpolation between, details from different data relating to the features. The data used to generate the image on the T V screen are updated in AGDT after each modification, and the T V screen is continuously refreshed from the store within AGDT. Earlier systems for constructing a pictorial representation of a human face comprise an arrangement for making a combination of drawings or photographs of facial features selected from a kit. The quality of the representation achieved is limited by the fixed combinations of details appearing on the available drawings or photographs in the kit, and by the mismatches in tones or shading and gaps that tend to occur at the edges of the drawings or photographs combined together. The system developed at the CAD Centre allows more convenient, accurate and flexible adjustment of the representations formed. Figures 1 - 3 are photographs taken from the TV screen. Figure 1 is a television picture of a genuine person and the others are composites. The changes that have been made to arrive at this series can easily be traced. From Figure 1, changes to the mouth and nose produced Figure 2, then changes to the eyes and hair oroduced Figure 3.
Figure 3. Changed mouth, nose, eyes and hair
183