ChapterPDF Available

Segmentation-Based Morphological Interpolation of Partition Sequences

Authors:

Abstract and Figures

A new algorithm for partition sequence interpolation is proposed. In a coding context, such a tool is necessary to reach high compression rates. Our scheme relies on a region-by-region approach. We propose a region ordering, based on an error criterion. Before ordering, some regions are merged according to a motion criterion. The shape of each region changes continuously, and the intermediate images are built from the new shaped regions with a dead leave model.
Content may be subject to copyright.
Region
Parametrization
Region
Partition
Ordering
Creation
Interpolated Partitions
Region
Interpolation
Initial Partitions
L2
L1
AB
... This approach estimates the evolution of the partition by computing a geodesic distance [18], [27] between the regions in the known partitions. Therefore, as pointed out in [4] and [18], this approach is only feasible when regions slightly vary their position between the two known partitions. If this is not the case, the evolution of each region has to be separately analyzed. ...
... If this is not the case, the evolution of each region has to be separately analyzed. A second approach is to analyze the partition in a regionby-region basis [4]. The evolution of each region is predicted independently. ...
... This approach does not make any a priori assumption on the movement of the regions. However, in the work presented in [4], the procedure to predict the region evolution is based on the definition of a geodesic distance. This procedure does not allow causal prediction, since geodesic distances are only defined between the regions from the two known partitions. ...
Article
This paper presents a prediction technique for partition sequences. It uses a region-by-region approach that consists of four steps: region parameterization, region prediction, region ordering, and partition creation. The time evolution of each region is divided into two types: regular motion and shape deformation. Both types of evolution are parameterized by means of the Fourier descriptors and they are separately predicted in the Fourier domain. The final predicted partition is built from the ordered combination of the predicted regions, using morphological tools. With this prediction technique, two different applications are addressed in the context of segmentation-based coding approaches. Noncausal partition prediction is applied to partition interpolation, and examples using complete partitions are presented. In turn, causal partition prediction is applied to partition extrapolation for coding purposes, and examples using complete partitions as well as sequences of binary images--shape information in video object planes (VOPs)--are presented.
... Two other approaches based on the above have also been presented in [4, 5]. Another kind of the morphological interpolation, presented in [3, 10] can be called a morphological 'intra-frame' interpolation. It deals with a single incomplete image and reconstructs its surface starting from given image fragments. ...
Conference Paper
Full-text available
Morphological interframe interpolation transforms one binary object into another thorough their metamorphosis producing a series of consecutive objects converting the initial object into the final one. Several mathematical morphology approaches have already been proposed for interframe image interpolation, however their definitions were different. In this paper a unified formula for the interpolation is given - an universal interpolator, which covers the existing morphological interpolation schemes. Due to its flexibility, it also allows constructing new interpolators according to one's particular needs.
... There are other papers dealing with geometrical and morphological processing of label images, but which do not use our label morphology. In [8], motion interpolation between two images in a sequence (that is, estimating the frames at time t þ aD, 0 < a < 1, from the two frames at times t and t þ D) was solved by segmenting both images, establishing a correspondence between objects in both images, labelling these objects, and finally interpolating the two resulting label images with geometrical and morphological operations. In [27], the ''average" of a set of label images is obtained by associating to each pixel the label minimizing the average of the pixel's signed distance transforms among the images (if several proper labels minimize it, the pixel is classified ''ambiguous", which corresponds to label >). ...
Article
Morphological operators based on the numerical ordering of grey-levels are used to filter regional minima and maxima in images. It is argued that label images constitute an appropriate framework for morphological filtering of regions which are neither minima nor maxima. Following a previous paper where we introduced morphological operations on label images [C. Ronse, V. Agnus, Morphology on label images: flat-type operators and connections, Journal of Mathematical Imaging and Vision 22 (2/3) (2005) 283–307], we study geodesic dilation (or erosion) and reconstruction. Since the lattice of label images is not distributive, some strange results may happen, so the standard definition of geodesic dilation and reconstruction must be modified in order to be effective; standard properties of geodesic operations are preserved only if we make some restrictions on the labels present in the mask or marker image. We give the relation between geodesic reconstruction and the flat zone connection on label images. We illustrate the theory with an application of morphology and geodesy on label images, to the segmentation of moving objects in video sequences.
Chapter
The importance of developing coding-oriented spatial segmentation techniques is stated. The specific problems of image sequence segmentation for coding purposes are analyzed. In order to both overcome such problems and improve the performance of segmentation-based coding schemes, a general segmentation structure is defined. This structure has five main steps: Partition projection, Image modeling, Image simplification, Marker extraction and Decision. In order to validate it, two different implementations of this structure are presented. The first utilizes a compound random field as image sequence model whereas the second relies on morphological tools.
Chapter
The time necessary to follow a path defined on a grey scale image is defined as the sum of the image values along the path. The geodesic time associated with two points of the image is nothing but the smallest amount of time necessary to link these two points. Starting from this notion, we define a new geodesic metric on the image plane: the generalized geodesic distance. The generalized geodesic distance betweeen two points is the length of the shortest path(s) linking these points in a minimum amount of time. This distance is used for defining a propagation function. Applications to shape description and interpolation from contour data are provided.
Article
A mosaic image is a partition of the plane. Each class of the partition has a label. Such partitions are produced, in particular, when using object-oriented image coding. The present study introduces an interpolation technique for mosaic images. The results obtained for mosaic images extend simpler techniques designed for binary images, that we present first.
Conference Paper
A hierarchical blockmatching algorithm for the estimation of displacement vector fields in digital television sequences is presented. Known blockmatching techniques fail frequently as a result of using a fixed measurement window size. Using distinct sizes of measurement windows at different levels of a hierarchy, the presented blockmatching technique yields reliable and homogeneous displacement vector - fields, which are close to the true displacements, rather than only a match in the sense of a minimum mean absolute luminance difference. In the environment of a low bit rate hybrid coder for image sequences, the hierarchical blockmatching algorithm is well suited for both, motion compensating prediction, and motion compensating interpolation. Compared to other high sophisticated displacement estimation techniques, the computational effort is decreased drastically. Due to the regularity and the very small number of necessary operations, the presented hierarchical blockmatching algorithm can be implemented in hardware very easily.
Article
This paper deals with a hierarchical morphological segmentation algorithm for image sequence coding. Mathematical morphology is very attractive for this purpose because it efficiently deals with geometrical features such as size, shape, contrast, or connectivity that can be considered as segmentation-oriented features. The algorithm follows a top-down procedure. It first takes into account the global information and produces a coarse segmentation, that is, with a small number of regions. Then, the segmentation quality is improved by introducing regions corresponding to more local information. The algorithm, considering sequences as being functions on a 3-D space, directly segments 3-D regions. A 3-D approach is used to get a segmentation that is stable in time and to directly solve the region correspondence problem. Each segmentation stage relies on four basic steps: simplification, marker extraction, decision, and quality estimation. The simplification removes information from the sequence to make it easier to segment. Morphological filters based on partial reconstruction are proven to be very efficient for this purpose, especially in the case of sequences. The marker extraction identifies the presence of homogeneous 3-D regions. It is based on constrained flat region labeling and morphological contrast extraction. The goal of the decision is to precisely locate the contours of regions detected by the marker extraction. This decision is performed by a modified watershed algorithm. Finally, the quality estimation concentrates on the coding residue, all the information about the 3-D regions that have not been properly segmented and therefore coded. The procedure allows the introduction of the texture and contour coding schemes within the segmentation algorithm. The coding residue is transmitted to the next segmentation stage to improve the segmentation and coding quality. Finally, segmentation and coding examples are presented to show the validity and interest of the coding approach.
Conference Paper
This paper presents an interpolation/extrapolation technique for sequence partitions. It consists of four steps: region parametrization, region interpolation, region ordering and partition creation. The evolution of each region is divided into two types: regular motion and random deformations. Both types of evolution are parametrized by means of the Fourier descriptors of the regions and they are separately interpolated in the Fourier domain. The final interpolated partition is built from the ordered combination of the interpolated regions, using morphological tools
Article
The Hausdorff distance measures the extent to which each point of a model set lies near some point of an image set and vice versa. Thus, this distance can be used to determine the degree of resemblance between two objects that are superimposed on one another. Efficient algorithms for computing the Hausdorff distance between all possible relative positions of a binary image and a model are presented. The focus is primarily on the case in which the model is only allowed to translate with respect to the image. The techniques are extended to rigid motion. The Hausdorff distance computation differs from many other shape comparison methods in that no correspondence between the model and the image is derived. The method is quite tolerant of small position errors such as those that occur with edge detectors and other feature extraction methods. It is shown that the method extends naturally to the problem of comparing a portion of a model against an image