Digital Image Processing

S. Manimurugan ¹, Neethu Rajan ²

Affiliations
1 Department of Computer Science and Engineering in Anna University, Coimbatore, IN
2 Department of Computer Science and Engineering at Karunya University, IN

Abstract

Now a day's large amount of medical image sequences are available in hospital and medical centers. The solution is the application of lossless compression so that we can get the exact replica of the original medical images. JPEG-LS is a lossless compression technique which provides a better compression rate and good visual quality. Lossless compression techniques remove spatial redundancy with in an image. Also, the temporal redundancy can be removed. By using efficient lossless compression techniques redundancy between and within medical images can be removed. This paper proposes a method that combines the JPEG-LS and an interframe coding with motion vectors to enhance the compression performance of using JPEG-LS alone. Since the interframe correlation between two adjacent images in a medical image sequence is usually not as high as that in a general video image sequence, the interframe coding is activated only when the interframe correlation is high enough. Here a motion vector sharing method is used for improving the quality of the compressed images. This paper proposes a method that enables sharing of motion vectors in different regions. The cost of storing the reference to another motion vector is much lower than the cost of storing the whole motion vector. This paper proposes a method that combines lossless compression of medical image sequences and the motion vector sharing technique.

Keywords

JPEG-LS, Motion Estimation, Motion Compensation, Motion Vector Sharing.

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S. Manimurugan ¹, Neenu Sebastian ²

Affiliations
1 Anna University, Coimbatore, IN
2 Karunya University, IN

Abstract

Digital Technology has matured to become predominant technology for creating, processing, transmitting and storing a information, a form of knowledge and intellectual assets. Digital image forgery is a growing problem in criminal cases and in public discourse. Photographic fakes can be used to promote a magazine story, defame a political opponent, or other objectives. Digital image forensic tools are helping to investigate and solve crimes. Realizing that it might be impossible to develop a method that is universal for all kinds of images and JPEG is the most frequently used image format, here an approach that can detect doctored JPEG images is proposed. In the proposed method the difference in the JPEG compression qualities within the forged image is used for detecting the forgery performed. Finally, automatic tampering detection and location of tampered region are fulfilled by image segmentation.

Keywords

Digital Forgeries, Segmentation, JPEG Ghost, Global Thersholding.

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S. Manimurugan ¹, N. Praveen Kumar ²

Affiliations
1 Anna University, Coimbatore, IN
2 Aditya Engineering College, Surampalem, East Godavari district, Andhra Pradesh, IN

Abstract

In this paper, we introduce a restoring the original image that was based on image properties when defining the interaction between pixels in the filtering process. After this, image structure is identified using properties like intensity level and is implemented according to the proposed technique. Using the generation of red points in this technique. In this context, a red points can be generated on to the image to find the similar neighborhood pixels like this different number of points can be generated on to image in order to provide interaction between pixels and identifying similar number of pixels and the weighted probability density function can be calculated for each group of similar pixels that for each window by using this information an original image can be restored. Calculating the average for the obtained weighted probability density function values can gives original restored value.

Keywords

Gaussian Noise, Weighted Probability Density Function, Mean, Image Restoration.

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S. Manimurugan ¹, Sherin Soman ²

Affiliations
1 Department of Computer Science and Engineering in Anna University, Coimbatore, IN
2 Department of Computer Science and Engineering in Karunya University, Coimbatore, IN

Abstract

For the reconstruction of fragmented images and objects a variety of image fragments need to be examined and reassembled. This problem often occurs in several scientific fields, where the manual reassembly of image fragments is very difficult. As the number of image fragments increases and the fragments are irregular in shape, it requires great amount of time and effort for the reassembly. This paper presents an effective reassembly technique for irregular image fragments and the restoration of cracks in the reassembled images. Here the spatial color histogram and the histogram intersection with each fragment is calculated. Then the contour pixel of each fragment is estimated. After the reassembly of image fragments, cracks can be formed. These cracks can be removed using the inpainting technique. The inpainting algorithm, which implements the filling of damaged region with impressive results. The core focus of the reassembly technique is on how to reassemble as many fragments as possible and at the same time to reduce the false matching contour pixels and to remove the cracks formed in the reconstructed image. We have analyzed the performance of the proposed reassembly technique using different number of image fragments and obtained satisfactory results.

Keywords

Crack, Fragment, Inpainting, Restoration.

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S. Manimurugan ¹, K. Porkumaran , Sherin Soman ²

Affiliations
1 Anna University, Coimbatore, IN
2 Karunya University, IN

Abstract

A variety of image fragments need to be reassembled inorder to reconstruct images and objects. This is a problem often encountered in several applications, ranging from archeology to medicine. The research focus of Image Fragments Reassembly Technique is on how to reassemble as many fragments as possible and at the same time to reduce the false matching error rate. The manual reassembly of image fragments is very difficult. It requires great amount of time, skill and effort. Thus, the automatic reassembly of image fragments is very important and can lead to a faster and more efficient reassembly. There are many techniques available for reassembling image fragments. This paper presents a survey of different reassembly techniques for image fragments and their performances. All these reassembly techniques can lead to a significant reduction in the human effort involved.

Keywords

Archaeology, Fragment, Matching, Reconstruction.

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S. Manimurugan ¹, K. Porkumaran , Neenu Sebastian ², Neethu Rajan ²

Affiliations
1 Anna University, Coimbatore, IN
2 Karunya University, IN

Abstract

Today images are widely used for the authentication purposes. For example in digital watermarking, visual cryptography etc, we use images for the authentication. Here images are transmitted from sender to receiver through a communication network, where they are processed for ensuring the authentication. While transmitting the images we must ensure that it is compressed effectively without losing the quality of image. Another threat while sending the image through network is that, it can be accessed and modified by a third party easily. This will affect the integrity of the image and it cannot be used for the authentication purposes. For ensuring a better usage of image for authentication purposes our approach uses the JPEG LS compression technique, which provides a better compression rate and good visual quality. For checking the integrity of image here the JPEG Ghost technique is used.

Keywords

Compression, Digital Forgeries, JPEG Compression, JPEG Ghost, JPEG LS.

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