In order to reduce the computational complexity for the high-efficiency video coding standard, an algorithm is proposed. First, we create a histogram based on the distribution of gray values in each coding tree unit. By using a self-correlation function of the gray histogram, we can skip some of the depth levels that are unnecessary. Second, the relationship between the sum of absolute transformed difference (SATD) and coding unit (CU) is used to decide an early termination for the split of the current CU, if the minimum SATD of this CU is smaller than a threshold. Experimental results show that the proposed algorithm can save an average of 38.39% of the encoding time with negligible degradation of coding efficiency compared with the reference model HM10.1.
A new images segmentation scheme, which is based on combining technique of fractal dimension and self-organization
neural network clustering, was presented in this paper. As we know features extracting is a very important step in image
segmentation. So, in order to extract more effective fractal features from images, especially in the remote sensing images,
a new image feature extracting and segmentation method was developed. The method extracts fractal features from a
series of images that are obtained by convolving the original image with various masks to enhance its edge, line, ripple,
and spot features. After that a 5-dimension feature vector are procured, in this vector each element is the fractal
dimension of original image and four convolved images. And at last, we segment the image based on the strategy that
combining the nearest neighbor classifier with self-organization neural network. Applying the presented algorithm to
several practical remote sensing images, the experimental results show that the proposed method can improve the feature
description ability and segment the images accurately.
A novel image fusion algorithm based on wavelet transform and edge keeping method is proposed in this paper. After
DWT the image is decomposed into different frequency bands. The spatial frequency and the contrast within the
low-frequency sub-band of the image are measured to determine the best choice of low-frequency component of the
fused image. As to the high-frequency sub-band of the image, the coefficients with maximal absolute grads values are
selected. The experimental results show that the proposed algorithm can preserve most useful information of original
images, and the clarity and contrast of the fused image are improved comparing with the original images.
As a major method for intellectual property right protecting, digital watermarking techniques have been widely studied
and used. But due to the problems of data amount and color shifted, watermarking techniques on color image was not so
widespread studied, although the color image is the principal part for multi-medium usages. Considering the
characteristic of Human Visual System (HVS), an adaptive color image watermarking algorithm is proposed in this paper.
In this algorithm, HSI color model was adopted both for host and watermark image, the DCT coefficient of intensity
component (I) of the host color image was used for watermark date embedding, and while embedding watermark the
amount of embedding bit was adaptively changed with the complex degree of the host image. As to the watermark image,
preprocessing is applied first, in which the watermark image is decomposed by two layer wavelet transformations. At the
same time, for enhancing anti-attack ability and security of the watermarking algorithm, the watermark image was
scrambled. According to its significance, some watermark bits were selected and some watermark bits were deleted as to
form the actual embedding data. The experimental results show that the proposed watermarking algorithm is robust to
several common attacks, and has good perceptual quality at the same time.
In this paper, we propose a new blind watermarking algorithm for images which is based on tree structure. The algorithm
embeds the watermark in wavelet transform domain, and the embedding positions are determined by significant
coefficients wavelets tree(SCWT) structure, which has the same idea with the embedded zero-tree wavelet (EZW)
compression technique. According to EZW concepts, we obtain coefficients that are related to each other by a tree
structure. This relationship among the wavelet coefficients allows our technique to embed more watermark data.
If the watermarked image is attacked such that the set of significant coefficients is changed, the tree structure allows the
correlation-based watermark detector to recover synchronously. The algorithm also uses a visual adaptive scheme to
insert the watermark to minimize watermark perceptibility. In addition to the watermark, a template is inserted into the
watermarked image at the same time. The template contains synchronization information, allowing the detector to
determine the geometric transformations type applied to the watermarked image. Experimental results show that the
proposed watermarking algorithm is robust against most signal processing attacks, such as JPEG compression, median
filtering, sharpening and rotating. And it is also an adaptive method which shows a good performance to find the best
areas to insert a stronger watermark.
In order to reduce the influence of noise on edge extracting and improve the precision of edge localization on the
image, after analyzed the principle, strong points and short points of some traditional edge detecting methods, an
effective algorithm for edge extracting in noise image was proposed in this paper. Adopting thought of traditional
multi-directional and multistage combinational filtering, an image detail-preserving adaptive filter is designed to
remove noise, and then extract the edge in the image. On the basis of the classical Sobel operator, we introduced an
algorithm with resisting noise, good real-time and locating accurate edge. The algorithm can distinguish real edge
from noise in terms of the theory of successive and smooth edge and random noise. The algorithm was
accomplished under visual C++ 6.0 environment and tested by several standard images. The experimental result
prove that the presented method is feasible and effective when the salt-pepper pollution of image is smaller than
15%, furthermore the method can extract edges with high location precision and good continuity accurately and
effectively, at the same time, it has high processing speed.
The common seven-core well logging cable can be able to transmit the maximum rate of 200kb/s for base band signal.
This situation causes great difficulty in increasing signal transmission rate. In this paper, a high-speed well-logging cable
telemetry system scheme was proposed. Based on correlative encoding and considered perpendicular multi-levels
amplitude modulation to increase carrying signal for each code at the same time, and adopted equilibrium technique in
time domain to spread the transmission bandwidth of well logging cable, a high-speed well-logging cable telemetry
system scheme was designed. The simulated results indicate that after technique improving, the transmitting rate of
seven-core well logging cable may be increased up to 400-500kb/s. This system has the advantages of taking less space,
low power consumption, transmitting faster and easy for repairing or upgrading. Also the system can meet the basic need
of the data transmitting speed demand of imaging well-logging system at the time begin.
It is well known that in the H.264 video coding standard the image inner spatial correlation had been made full use in its
intra-frames prediction algorithm, so the encoding efficiency can be improved. However, in H.264 video coding standard,
no matter prediction frames (P-frame or B-frame) or intra-frames (I-frame), all of them need to carry on predicting at
each macro block inside the frame, and the algorithm utilizes the surrounding pixels to predict, therefore it improves the
encoding efficiency at the cost of increasing calculation complexity of the encoder. For the sake of real time video
communications, it is necessary to employ a new algorithm to reduce calculating complexity for intra-frames predicting
and speed up encoding procedure. For these reasons, a modified fast intra-frames prediction pattern decision algorithm
was proposed in this paper. Using directional information of luminance pattern and chrominance pattern to decide the
candidate pattern, the limited of edge direction can restrict the number of the candidate pattern, so the algorithm can
greatly decrease the number of candidate patterns, therefore it can obviously cut down calculating amount. At the same
time, the proposed algorithm also adopts early termination of 4×4 block pattern selection strategy to choose the most
possible pattern. The proposed algorithm has the ability of obviously reducing the pattern selecting calculation
complexity, which has been approved by the experimental result. So the algorithm is possible to be used in the real time
As we known that under the same image reconstruction quality, the encoding efficiency of H.264 video standard is about
50% higher than that of H.263 standard. But at the same time, this methodology improving the encoding efficiency based
on the rate distortion optimizing (RDO) and the multi patterns motion estimating; as a result it is greatly increasing the
calculation complexity of encoder, and greatly affects the video compression speed. Therefore, when we estimate motion
pattern of a video sequence, if the best predicting pattern can be decided as quickly as possible, and unnecessary
predicting pattern searching can be limited or costly computation can be cut down, then it is possible to speed up the
motion estimation. Under these thought, a fast inter-frames pattern selecting and motion pattern estimating algorithm was
proposed in the paper. Based on the texture feature and local motion character of current macro block (MB), a set of
effective predicting patterns were selected. This selection can effectively reduce searching time of follow up predicting
pattern; so it can obviously decrease the operation complexity of the encoder, and improve the searching speed for the
In H.264 video coding standard, the combination encoding frame was adopted. It introduces some new algorithms, and
modifies several aspects of the encoding scheme. So the encoding scheme improves the encoding efficiency obviously.
But the H.264 standard is not supporting FGS encoding. So a H.264 based self-adaptive FGS (Fine Granular
Scalable)(H.264-FGS) encoding scheme is proposed in this paper. In this encoding scheme, the base layer of encoder is
keeping H.264 encoder architecture, which consists of the motion estimation, motion compensation, intra predictive,
integer transformation, loop filtering, content based arithmetic encoding, and etc. In the base layer generated block we
obtain base code flux of FGS. Subtracting the original image from the reconstruction image of the base layer, we get the
residual error. Then after the DCT transform and the variable length encoding compresses, we obtain the enhanced code
flux of FGS.
Compared with the original MPEG-4 FGS encoding scheme, the proposed FGS encoding scheme has the feature of
increasing encoding efficiency by 1~3 dB and keep the all properties that MPEG-4 FGS encoding technology provided.
Morphology is an importance method in image processing and computer vision technique. Now as we know that
morphology has been widely used in grayscale and bi-level image processing, but it is difficult to use in color image
processing, for color image has three color components. Applying morphological method on color image may cause
color shift in the original image. Morphological image processing method has satisfactory results in noise restraining,
image enhancing, image encoding, feature extracting, and texture analyzing. So it is important to find out a method for
applying morphological method on color image, and keep the color unchanged at the same time. An approach for color
image morphological transform was put forward in this paper. In our approach, we change the color model from RGB
space to HIS space first, then applying morphological transform on I component in HSI space and keeping H and S
components unchanged, finally using this new I component and two other components (H and S) to obtain color image
in RGB space. In this paper we define some new color morphological operators for color image morphological
transform, and their characters were also discussed. Experimental results were also explained in the paper. Color
morphological transform is a prolonging application of morphology in color space. We find it is an effective means in
image processing and feature extracting of target shape.
A scheme to realize static image and video code and decode based on TI DSP chip TMS320C6416 was proposed in
this paper, and a reliable image transmission system was developed. According to the application demand, the
software has six major modules: (1) initialization of DSP chip and other hardware; (2) video acquisition and input
control program; (3) serial port communicating program; (4) RAM storage and communicating program that applies
and releases the token-ring; (5) video reconstruct and output control; (6) the major parts of the software, encoding and
decoding program, in which wavelet was applied first, then run length coding and Huffman coding were carried out,
the image or video could had balance resolution and better visual effect by adaptive processing, in the decoding parts,
the reverse operation were executed. After the system line up debugging was carried out, a satisfying result was
reached: the comparatively high compression rate, preferable image quality and relatively real-time result.
With the rapid growth of network distributions of information like image, video and etc, there is an urgent need for copyright protection against pirating. As an effective method for ownership identification, digital watermarking technique arouses much interesting around the corresponding scientists. And much study is focused on information hiding technique. In this paper we propose a novel technique for watermarking. The technique was considered on other side of copyright protection: using mark when the watermark was embedded, if the watermarked image was attacked, we first distinguish the attack method, and then take the corresponding means to lessen or remove the effect of attack. As a result satisfactory extracted watermark can be obtained. In the proposed technique, usually we chose the length of mark sequence is much smaller than the pixel number in the sub-band, and the mark sequence can also be scrawled by spread spectrum code. So it is considerably powerful in resisting the clipping operation. This means the estimation of the attack type may be considerably accurate. Therefore the algorithm has the merit of robustness, strong anti-attack ability and security.
Proc. SPIE. 6247, Independent Component Analyses, Wavelets, Unsupervised Smart Sensors, and Neural Networks IV
KEYWORDS: Wavelet transforms, Image compression, Detection and tracking algorithms, Image processing, Wavelets, Digital watermarking, Discrete wavelet transforms, Digital imaging, Signal processing, Information security
Different digital watermarking schemes had been proposed to address this issue of ownership identification. Early work on digital watermarking focused on information hiding in the spatial domain or transform domain respectively. Usually the watermark recovered result was not as satisfaction as the demand. Some multi-describing techniques were proposed for watermark embedding lately. Enlightened by these techniques, a novel blind digital image watermarking algorithm based on multi strategy is put forward in this paper. The watermark is embedded in multi-resolution wavelet transform domain of the original image. Based on spread spectrum techniques, the algorithm is composed of three new techniques to improve robustness, imperceptibility and security. These new techniques are as follow:
First, multi- intensity embedding technique is adopted in the embedding process. Because the intensity of watermark has different influences to wavelet coefficient in different resolution layer, so using different intensity in corresponding layer, we can gain the merit of stronger anti-attack ability and imperceptibility
Second, applying spread spectrum code to permute the original watermark so a new scrambling watermark is established. By reducing the effect of destroyed watermark image, the technique has the ability of anti-clipping, moreover, the technique improves the security of watermarking for needing scrawling password to extract the original watermark.
Third, interlaced watermark embedding technique is introduced. In this technique, we interlace several copies of watermark in different resolution to embed in wavelet transform domain. As a result the recovered watermark is shown better performance after various attacks.
Applying CDMA techniques to optical communications and combining CDMA techniques with optical communication has its advantages, which not only keeps the characteristics of CDMA techniques in wireless communication, such as interference immunity, secrecy, soft capacity and simple network protocol, but also make use of the huge bandwidth of fiber. Therefore, optical CDMA communication system has the virtue of asynchronism, broad band and reliable. In this paper, we have done tasks as below: first we thoroughly study the development and recent progress in 2-D time / frequency domain optical CDMA encoding schemes. Then we put forward an implement encoding/ decoding scheme based on optical time spreading/ frequency hopping to solve the problem in current schemes. The scheme adopts 2-D time / frequency domain combination codes as address codes, by assigning two orthogonal address codes to each user and encoding "1" and "0" to these address codes respectively, in sink side differential detection technique is adopted. The scheme has the advantage of increasing power efficiency and improving system performance. While under the condition that two branches are balance, the best judge threshold of system is not variety with the environment, so the scheme also has the merit of lower systemic complexity.
Digital watermarking technique provides an effective way to protect the image. A detecting scheme for digital image watermarking, which using principal components of the watermarked image, was proposed in this paper. The scheme was based on DWT and DCT, and using principal components of the watermarked image at the same time, As we know that the principal components of an image has the virtue of insensitivity to geometrical transform, filtering and rotating operation, so using this character for watermark detecting should have the same merit. The course of the scheme is as follow: first, the original image was decomposed by 2-D discrete wavelet transform and the detail sub-bands are reserved, then the approximation image is transformed by discrete cosine transform and embedded with watermark image. At the stage of watermark detection, The DWT and DCT were carried out first, at the same domain we extract the embedded watermark, which was corrupted by attacks. Then applied principal components transform to the corrupted image to restore the watermark. After processing, the restored watermark had least mean square error with the original watermark image. The experimental results showed its good unification between the robustness and insensitivity, and the quality of detected watermark is improved greatly at the same time.
As we know that morphology is the technique that based upon set theory and it can be used for binary image processing and gray image processing. The principle and the geometrical meaning of morphological boundary detecting for image were discussed in this paper, and the selecting of structure element was analyzed. Comparison was made between morphological boundary detecting and traditional boundary detecting method, conclusion that morphological boundary detecting method has better compatibility and anti-interference capability was reached. The method was also used for L.V. cineangiograms processing. In this paper we hoped to build up a foundation for automatic detection of L.V. contours based on the features of L.V. cineangiograms and Morphological theory, for the further study of L.V. wall motion abnormalities, because wall motion abnormalities of L.V. due to myocardia ischeamia caused by coronary atherosclerosis is a significant feature of Atherosclerotic coronary heart disease (CHD). An algorithm that based on morphology for L.V. contours extracting was developed in this paper.
Atherosclerotic coronary heart disease (CHD) is one of the commonest diseases that is heavily hazardous to people's health. Wall motion abnormalities of L.V. due to myocardia ischeamia caused by coronary atherosclerosis is a significant feature of CHD. This paper was designed to build up a foundation for automatic detection of L.V. contours according to the features of L.V. cineangiograms, for a further study of L.V. wall motion abnormalities. An algorithm that based on morphology for L.V. contours extracting was developed in this paper. As we know morphology is a kind of technique based upon set theory and it can be used for binary image and gray image processing. The principle and the geometrical meaning of morphological boundary detecting for image were discussed in this paper, and the selection of structuring element was analyzed. Comparison was made between morphological boundary detecting and traditional boundary detecting method, conclusion that morphological boundary detecting method has better compatibility and anti-interference capability was reached.
Image matching method is an important technique in image processing. It gives reference and methodology to fully use different kinds of data. An image matching method based on invariant features of image and image data basis generating method are presented in this paper. The method is realized by following procedures: first, we establish the image data basis, then we change the newly obtained image to the scale of the base image, and finally we use invariant features of image to correlate the base image and the newly obtained image, in this way to find the best matching point. At the same time, a fast algorithm is introduced in this paper to calculate the invariant features of image. The method is insensitive to translation, rotation and scale, also it is simple and stable.
As we know, a main problem in image classification and explanations the segmentation of image. Use of the boundary contour rather than most of other preprocessed data help in simpler image representation, registration, and identification. Thus the problems of edge detection and contour following have been widely addressed with proposed solutions ranging over simple thresholding, signal processing, filtering techniques, and definition of admissible edge profile function, etc. Most of these techniques seem to be complex and time consuming. To solve the conflict between noise and time consume, this paper presents a fast method for detecting the contour of images. It consists of three steps: first, reduce the image noise by using a high frequency noise sensitive smoothing operator; second, detect the edge by using an algorithm based on modified Sobel operator; and third, follow the boundary contour and determine the area of interesting in the image. The results of experiment show that the method is fast and accurate.
In order to render the virtual terrain environment in real-time, a view-dependent continuous LOD algorithm is presented in this paper. We analyze the regularity of the regular grid Digital Elevation Model and employ three view-dependent criteria to reduce the complexity of the terrain in real-time: (1) screen space error; (2) view-frustum intersection; (3) node orientation. The experiment results indicate that this algorithm can attain a much higher frame rate in rendering the virtual terrain environment, as well as in maintaining the visual quality.