Usual segmentation techniques of grayscale images depend on supervised trial-and-error procedures. Moreover, in noisy images, local classi ̄cation schemes fail due to the random °uctuations introduced by the noise. Recent proposals as the active contours may be robust enough to cope with some cases of noisy images without supervision (except for the initialization step), but still fail with imag...

Suppose the binary images shown in Figure 1 were transmitted over a binary symmetric channel (BSC). What could be done to clean up or denoise the resulting noisy images? A quick scan of the image processing literature suggests the use of such algorithms as median filtering and morphological filtering. In the binary case a median filter replaces each pixel in the noisy image by the color of the ...

In this paper, we propose an unsupervised color image classification algorithm based on a Markov random field (MRF) model. In the MRF model, we use the CIE-luv color metric because it is close to human perception when computing color differences. On the other hand, intensity and chroma information is separated in this space. Without parameter estimation, our model would not be useful in real-li...

In this paper a hybrid denoising algorithm which combines spatial domain bilateral filter and hybrid thresholding function in the wavelet domain is proposed. The wavelet transform is used to decompose the noisy image into its different subbands namely LL, LH, HL, and HH. A two stage spatial bilateral filter is applied. The first stage is applied on the noisy image before wavelet decomposition. ...

This paper presents an algorithm for image registration and mosaicing on underwater sonar image sequences characterized by a high noise level, inhomogeneous illumination and low frame rate. Imaging geometry of acoustic cameras is significantly different from that of pinhole cameras. For a planar surface viewed through a pinhole camera undergoing translational and rotational motion, registration...

We attack the problem of robust and eecient image compression for transmission over noisy channels. To achieve the dual goals of high compression eeciency and low sensitivity to channel noise we introduce a multimode coding framework. Multimode coders are quasi-xed length in nature, and allow optimization of the tradeoo between the compression capability of variable-length coding and the robust...

When a feedback channel is available from the receiver to the transmitter, adaptive schemes for source-channel coding can be used for image transmission. In this paper we see that the use of embedded source codes and embedded channel codes, when combined in a Hybrid ARQ protocol, can provide the desired exibility at high eeciency, low complexity and low feedback channel usage. We propose optimi...

Now a days remote sensing plays very important role in satellite based communication. Satellite gives images in digital format. Digital images are often corrupted during acquisition, transmission or due to faulty memory locations in hardware. The noise density varies depending on various factors namely reflective surfaces, atmospheric variations, noisy communication channels etc. Impulse noise ...

In this paper an algorithm that performs the tracking of points in a calibrated and noisy image sequence is presented. The candidate points to be tracked must satisfy certain constraints that can be deduced from the multiple view geometry. The idea is to consider as noisy points those candidates which cannot be tracked in the sequence. The robustness of the algorithm has been verified on simula...