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الكلية كلية تكنولوجيا المعلومات
القسم قسم البرامجيات
المرحلة 2
أستاذ المادة توفيق عبد الخالق عباس الاسدي
4/4/2011 6:17:35 PM
Image segmentation[ pratt]
Segmentation of an image entails the division or separation of the image into regions of similar attribute. The most basic attribute for segmentation is image luminance amplitude for a monochrome image and color components for a color image.
Image edges and texture are also useful attributes for segmentation.
There is no theory of image segmentation.. Haralick and Shapiro have established the following qualitative guideline for a good image segmentation: “Regions of an image segmentation should be uniform and homogeneous with respect to some characteristic such as gray tone or texture. Region interiors should be simple and without many small holes. Adjacent regions of segmentation should have significantly different values with respect to the characteristic on which they are uniform. Boundaries of each segment should be simple, not ragged, and must be spatially accurate.”
Image Segmentation [ RAY page 131]
The growing need for automated image analysis and interpretation in a wide range of applications necessitates the development of segmentation algorithms.
Segmentation involves partitioning an image into a set of homogeneous and meaningful regions, such that the pixels in each partitioned region possess an identical set of properties or attributes. These sets of properties of the image may include gray levels, contrast, spectral values, or textural properties. The result of segmentation is a number of homogeneous regions, each having a unique label.
An image is thus defined by a set of regions that are connected and nonoverlapping, so that each pixel in the image acquires a unique region label that indicates the region it belongs to.
Segmentation algorithms are based on one of the two basic properties of gray-level values discontinuity and similarity among the pixels.
In the first category of algorithms, we partition an image based on abrupt changes in gray level. The principal areas of interest within this category are the detection of lines and edges in an image. Thus if we can extract the edges in an image and link them, then the region is described by the edge contour that contains it.
We may view the process of segmentation from another perspective. From this point of view, the connected set of pixels having more or less the same homogeneous intensity form the regions.
The principal approaches in the second category are based on the similarity among the pixels within a region. While segmenting an image, various local properties of the pixels are utilized.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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