In order to improve the performance of the classical pixel-based image coding techniques, new tec... more In order to improve the performance of the classical pixel-based image coding techniques, new technical approaches are deemed necessary. These approaches aim at a better understanding of the image content, in terms of regions, textures, etc., thus "healing the blindness" of the old schemes. The new image coding approaches require the identification of regions or "objects", i.e., image segmentation. This process results in an image partition matrix, which includes contour information, and a set of parameters characterising each region according to a given set of image features. The contour information represents an extremely important and sensitive information for the human visual system, being thus also of great importance in the image coding context. This paper proposes a classification of partition and contour models according to a tree structure, in order to clearly identify the contour models to which contour coding techniques can be applied. It also proposes a lossless contour coding technique based on Freeman's chain codes [5].
In order to improve the performance of the classical pixel-based image coding techniques, new tec... more In order to improve the performance of the classical pixel-based image coding techniques, new technical approaches are deemed necessary. These approaches aim at a better understanding of the image content, in terms of regions, textures, etc., thus “healing the blindness” of the old schemes. The new image coding approaches require the identification of regions or “objects”, ie, image segmentation. This process results in an image partition matrix, which includes contour information, and a set of parameters ...
Very low bitrate video coding became in the last years one of the most important areas of image c... more Very low bitrate video coding became in the last years one of the most important areas of image communication due to the identification of several very low bitrate applications such as mobile videotelephony, multimedia mail, electronic newspapers, entertainment, traffic control, and interactive data bases. Since conventional video coding techniques are reaching a saturation point, a new generation of techniques, aiming at a deeper “understanding” of the image, is being studied. In this context, image analysis, particularly the identification of regions or objects in images (segmentation), is an important step in very low bitrate video coding, since it will lead to a better representation of images and consequently to an improvement of the encoded image quality (for a fixed bitrate). This paper describes a segmentation algorithm based on split & merge and shortest spanning trees (SST). The image is first split according to a quad tree structure and then the resulting regions are merged, us...
Recognising the importance of partition or shape coding in the field of image and video coding, a... more Recognising the importance of partition or shape coding in the field of image and video coding, and the fact that a systematisation of the subject would simplify the comparison of partition coding techniques, this paper proposes a classification of partition types and partition representations into a taxonomy tree. The partition type level of the tree classifies the possible partition types that may have to be coded. The partition representation level classifies the possible representations for each partition type.
This paper also overviews the partition coding techniques which address the considered partition types and which use the identified partition representations. Emphasis is given to binary partition coding techniques proposed within the framework of MPEG-4.
Very low bit-rate video coding has recently become one of the most important areas of image commu... more Very low bit-rate video coding has recently become one of the most important areas of image communication and a large variety of applications have already been identified. Since conventional approaches are reaching a saturation point, in terms of coding efficiency, a new generation of video coding techniques, aiming at a deeper "understanding" of the image, is being studied. In this context, image analysis, particularly the identification of objects or regions in images (segmentation), is a very important step. This paper describes a segmentation algorithm based on split and merge. Images are first simplified using mathematical morphology operators, which eliminate perceptually less relevant details. The simplified image is then split according to a quad tree structure and the resulting regions are finally merged in three steps: merge, elimination of small regions and control of the number of regions.
ELSEVIER Signal Processing: Image Communication 10 (1997) 519 SIGNAL PROCESSING: IMAGE COMMUNICAT... more ELSEVIER Signal Processing: Image Communication 10 (1997) 519 SIGNAL PROCESSING: IMAGE COMMUNICATION Partitions: A taxonomy of types and representations and an overview of coding techniques Manuel Menezes de Sequeira*, Diogo Cortez ...
In order to improve the performance of the classical pixel-based image coding techniques, new tec... more In order to improve the performance of the classical pixel-based image coding techniques, new technical approaches are deemed necessary. These approaches aim at a better understanding of the image content, in terms of regions, textures, etc., thus "healing the blindness" of the old schemes. The new image coding approaches require the identification of regions or "objects", i.e., image segmentation. This process results in an image partition matrix, which includes contour information, and a set of parameters characterising each region according to a given set of image features. The contour information represents an extremely important and sensitive information for the human visual system, being thus also of great importance in the image coding context. This paper proposes a classification of partition and contour models according to a tree structure, in order to clearly identify the contour models to which contour coding techniques can be applied. It also proposes a lossless contour coding technique based on Freeman's chain codes [5].
In order to improve the performance of the classical pixel-based image coding techniques, new tec... more In order to improve the performance of the classical pixel-based image coding techniques, new technical approaches are deemed necessary. These approaches aim at a better understanding of the image content, in terms of regions, textures, etc., thus “healing the blindness” of the old schemes. The new image coding approaches require the identification of regions or “objects”, ie, image segmentation. This process results in an image partition matrix, which includes contour information, and a set of parameters ...
Very low bitrate video coding became in the last years one of the most important areas of image c... more Very low bitrate video coding became in the last years one of the most important areas of image communication due to the identification of several very low bitrate applications such as mobile videotelephony, multimedia mail, electronic newspapers, entertainment, traffic control, and interactive data bases. Since conventional video coding techniques are reaching a saturation point, a new generation of techniques, aiming at a deeper “understanding” of the image, is being studied. In this context, image analysis, particularly the identification of regions or objects in images (segmentation), is an important step in very low bitrate video coding, since it will lead to a better representation of images and consequently to an improvement of the encoded image quality (for a fixed bitrate). This paper describes a segmentation algorithm based on split & merge and shortest spanning trees (SST). The image is first split according to a quad tree structure and then the resulting regions are merged, us...
Recognising the importance of partition or shape coding in the field of image and video coding, a... more Recognising the importance of partition or shape coding in the field of image and video coding, and the fact that a systematisation of the subject would simplify the comparison of partition coding techniques, this paper proposes a classification of partition types and partition representations into a taxonomy tree. The partition type level of the tree classifies the possible partition types that may have to be coded. The partition representation level classifies the possible representations for each partition type.
This paper also overviews the partition coding techniques which address the considered partition types and which use the identified partition representations. Emphasis is given to binary partition coding techniques proposed within the framework of MPEG-4.
Very low bit-rate video coding has recently become one of the most important areas of image commu... more Very low bit-rate video coding has recently become one of the most important areas of image communication and a large variety of applications have already been identified. Since conventional approaches are reaching a saturation point, in terms of coding efficiency, a new generation of video coding techniques, aiming at a deeper "understanding" of the image, is being studied. In this context, image analysis, particularly the identification of objects or regions in images (segmentation), is a very important step. This paper describes a segmentation algorithm based on split and merge. Images are first simplified using mathematical morphology operators, which eliminate perceptually less relevant details. The simplified image is then split according to a quad tree structure and the resulting regions are finally merged in three steps: merge, elimination of small regions and control of the number of regions.
ELSEVIER Signal Processing: Image Communication 10 (1997) 519 SIGNAL PROCESSING: IMAGE COMMUNICAT... more ELSEVIER Signal Processing: Image Communication 10 (1997) 519 SIGNAL PROCESSING: IMAGE COMMUNICATION Partitions: A taxonomy of types and representations and an overview of coding techniques Manuel Menezes de Sequeira*, Diogo Cortez ...
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This paper also overviews the partition coding techniques which address the considered partition types and which use the identified partition representations. Emphasis is given to binary partition coding techniques proposed within the framework of MPEG-4.
This paper also overviews the partition coding techniques which address the considered partition types and which use the identified partition representations. Emphasis is given to binary partition coding techniques proposed within the framework of MPEG-4.