Digital Image Processing Techniques
APCOMS | DIGITAL IMAGE PROCESSING | ASSIGMNENT | | SIR SHAHID ISMAIL | 29-May-13 |
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GROUP MEMBERS:
USAID SHUAIB F-3313
AHMED TAUQIR F-3324
HAMMAD SHEIKH F-3325
GROUP MEMBERS:
USAID SHUAIB F-3313
AHMED TAUQIR F-3324
HAMMAD SHEIKH F-3325
Representation
Segmentation techniques yield raw data in the form of pixels along a boundary or pixels contained in a region. These data sometimes are used directly to obtain descriptors. Standard uses techniques to compute more useful data (descriptors) from the raw data in order to decrease the size of data.
Chain Codes
A chain code is a lossless compression algorithm for monochrome images. The basic principle of chain codes is to separately encode each connected component, or "blob", in the image. For each such region, a point on the boundary is selected and its coordinates are transmitted. The encoder then moves along the boundary of the region and, at each step, transmits a symbol representing the direction of this movement. This continues until the encoder returns to the starting position, at which point the blob has been completely described, and encoding continues with the next blob in the image.
This encoding method is particularly effective for images consisting of a reasonably small number of large connected components.
Some popular chain codes include the Freeman Chain Code of Eight Directions (FCCE), Vertex Chain Code (VCC), Three Orthogonal symbol chain code (3OT) and Directional Freeman Chain Code of Eight Directions (DFCCE).
Code chains are unacceptable because the resulting chain of codes tends to be quite long. Any small disturbances along the boundary due to noise or imperfect segmentation cause changes in the code that may not be related to the shape of the boundary. Solve the problems by resample the boundary by selecting a larger grid spacing however, different grid can generate different chain codes starting point is arbitrary. The chain code of a boundary is
|
GROUP MEMBERS:
USAID SHUAIB F-3313
AHMED TAUQIR F-3324
HAMMAD SHEIKH F-3325
GROUP MEMBERS:
USAID SHUAIB F-3313
AHMED TAUQIR F-3324
HAMMAD SHEIKH F-3325
Representation
Segmentation techniques yield raw data in the form of pixels along a boundary or pixels contained in a region. These data sometimes are used directly to obtain descriptors. Standard uses techniques to compute more useful data (descriptors) from the raw data in order to decrease the size of data.
Chain Codes
A chain code is a lossless compression algorithm for monochrome images. The basic principle of chain codes is to separately encode each connected component, or "blob", in the image. For each such region, a point on the boundary is selected and its coordinates are transmitted. The encoder then moves along the boundary of the region and, at each step, transmits a symbol representing the direction of this movement. This continues until the encoder returns to the starting position, at which point the blob has been completely described, and encoding continues with the next blob in the image.
This encoding method is particularly effective for images consisting of a reasonably small number of large connected components.
Some popular chain codes include the Freeman Chain Code of Eight Directions (FCCE), Vertex Chain Code (VCC), Three Orthogonal symbol chain code (3OT) and Directional Freeman Chain Code of Eight Directions (DFCCE).
Code chains are unacceptable because the resulting chain of codes tends to be quite long. Any small disturbances along the boundary due to noise or imperfect segmentation cause changes in the code that may not be related to the shape of the boundary. Solve the problems by resample the boundary by selecting a larger grid spacing however, different grid can generate different chain codes starting point is arbitrary. The chain code of a boundary is