Showing papers on "Bit plane published in 2016"

A robust color video watermarking scheme based on hybrid embedding techniques

Abstract: The advancements in network technologies and processing of multimedia contents have provided the way for the distribution and sharing of multimedia contents through networks. This in turn has increased the demand for protecting the multimedia contents in terms of authentication, proof of ownership, copy control etc., which can be achieved by means of what is called digital watermarking. The challenges in watermarking techniques are how to achieve the imperceptibility, robustness and payload simultaneously. This paper presents a new bit plane sliced, scrambled color image watermark embedded on the color cover video using hybrid transforms such as Contourlet Transform (CT), Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD) transformations with good imperceptibility, high robustness and at an information rate of (N ź number of motion frames) / 24 images per second of the video, where N is the total number of frames in the video. In order to achieve a good level of imperceptibility, we perform the following: First, we slice the color watermark image into 24 slices using the bit plane slicing mechanism. Subsequently, the so called Arnold transformation key is used to scramble those slices, to achieve first-level of security. Thus, an authenticated receiver with an appropriate key alone can descramble the received slices. Second, we embed those scrambled slices on one of the DWT mid-frequency coefficients (LH band) of successive 1-level CT non-motion frames of color cover video. The non-motion frames are identified using the histogram difference based shot boundary detection algorithm. Third, in order to the provide second-level of security, we generate a random eigen vector from the color watermark image, using co-variance matrix and maximum eigen value and then embed it on another DWT mid-frequency coefficients (HL band). Thus, embedding only the slices (not an entire image) will improve the level of imperceptibility. The mid-frequency embedding location can withstand against all low pass and high pass filtering attacks; thereby it increases the level of robustness. Thus, the proposed system is suitable for authentication. Finally, as far as payload is concerned, we need only 24 non-motion frames for embedding our watermark on to the cover video. Hence the remaining frames can be utilized for embedding other color images. Our simulation results prove that the proposed system provides trustworthy performance against various notable image processing attacks, multiple attacks, geometrical attacks, and temporal attacks.

An adaptive multi bit-plane image steganography using block data-hiding

Abstract: Embedding a secret message into the pixels of a cover image yields a visual distortion if these pixels belong to smooth regions. Thus, this prompted the development of some edge-based approaches in which only the edge pixels are used to hide secret bits. As a result, the visual quality of stego images is improved. However, the capacity is limited due to some unused regions in cover images. In this paper, an adaptive multi bit-planes image steganography using block data-hiding (MPBDH) is proposed. This method employs more than one bit-plane and applies an adaptive complexity threshold computation to select the complex regions of a cover image used in data hiding. Consequently, the embedding capacity and security performance are significantly improved in comparison with previous approaches based on pixel and block complexity. The results, which are obtained from experiments performed on 10,000 natural gray-images, indicate that the embedding capacity and security introduced in the proposed approach overcome the problems of previous approaches. The proposed approach is hence suitable for secure communications.

Reversible data hiding scheme based on histogram shifting of n-bit planes

Abstract: In this paper, a reversible data hiding scheme is proposed based on histogram shifting of n-bit planes (nBPs). This scheme extracts nBPs from an 8-bit plane for each pixel to generate the bit plane truncation image (BPTI), and then block division is used in the BPTI. These operations can make the peak point of the block histogram more concentrated and improve the probability of the zero point in the block histogram. The histogram shifting method was used to embed secret bits into the peak point in each block. Note that this block was not utilized to embed secret bits if the zero point of a certain block did not exist, thus, there was no overflow or underflow in our scheme when the histogram was shifted. Our proposed scheme achieved higher hiding capacity than previous histogram-based schemes, and its visual quality was very satisfactory. The experimental results validated the expected merits of the proposed scheme.

A modified blind image watermarking scheme based on DWT, DCT and SVD domain using GA to optimize robustness

Abstract: A modified blind image watermarking algorithm using discrete wavelet transform (DWT), discrete cosine transform (DCT) and singular value decomposition (SVD) is proposed in this paper. One level DWT operation is performed on original host image using Haar wavelet and approximation (LL) sub-band is selected to split it into two sub images. DCT and SVD operations are performed in both sub images using 8×8 block size. Based on pixels values of binary watermark image, singular value of first sub image is modified referring singular value of second sub image to embed watermark. Genetic algorithm (GA) technique is adopted to optimize visual quality and robustness of watermarked image. Peak Signal to Noise Ratio (PSNR) and Normalized Cross correlation (NCC) are computed to evaluate imperceptibility and robustness of the watermarked image. Experimental results obtained confirm that the proposed method is efficient and more robust against different attacks, viz. noise insertion, filtering, JPEG compression, histogram equalization, gamma correction, bit plane removal, image sharpening and cropping attacks.

Screen video encoding and decoding method based on progressive character block compression and encoding and decoding device

Abstract: The invention discloses a screen video encoding and decoding method based on progressive character block compression and an encoding and decoding device thereof The screen video encoding and decoding method comprises the following steps: obtaining a frame in a screen video, and dividing the frame into M*N macro blocks; dividing each macro block into character blocks or image blocks according to the category; dividing each character block into a plurality of character compression code streams according to a main color and a non-main color; encoding the main color by an index table, and progressively encoding escape colors of the non-main color based on a bit plane; dividing each image block into a plurality of image encoding quality layers by using a progressive image encoding algorithm based on wavelet transform; transmitting the code streams to a receiving terminal according to different quality grades; and decoding and displaying the code stream of each quality layer by the receiving terminal According to the screen video encoding and decoding method disclosed by the invention, in view of the limitation and defects of traditional character encoders, the progressive character encoding technology of a plurality of quality layers is realized, no support of special equipment is needed, and the screen video encoding and decoding method is applicable to all occasions needing to compress screen images containing characters

Selective gray-coded bit-plane based low-complexity motion estimation and its hardware architecture

Abstract: Today, many consumer electronics devices have video capturing capability which is one of the most time, power and memory consuming application. Motion estimation (ME) is the key part of the video coding process in terms of computational load. Thus, it is important to implement this process in a resource efficient way without degrading the encoding quality and real-time operation performance. Low bitdepth representation based ME methods draw a lot of attention in consumer electronics area mainly thanks to its highly efficient hardware and software implementations. However, these low bit-depth representation based methods generally assume that the low bit-depth images are already available. Furthermore, these methods simply neglect the binarization cost which is not a proper approach when whole encoding architecture is of concern. This paper presents a novel selective Gray-coding based ME method and its hardware architecture with an embedded system integration by making use of one of the most common interconnect architecture in consumer electronics devices. Experimental results show that it is possible to reduce computational load of binarization stage significantly while improving the ME accuracy by the proposed approach compared to methods at the same category.

Transmitter and shortening method thereof

Abstract: A transmitter is provided. The transmitter includes: an outer encoder configured to encode input bits to generate outer-encoded bits including the input bits and parity bits; a zero padder configured to constitute Low Density Parity Check (LDPC) information bits including the outer-encoded bits and zero bits; and an LDPC encoder configured to encode the LDPC information bits, wherein the LDPC information bits are divided into a plurality of bit groups, and wherein the zero padder pads zero bits to at least some of the plurality of bit groups, each of which is formed of a same number of bits, to constitute the LDPC information bits based on a predetermined shortening pattern which provides that the some of the plurality of bit groups are not sequentially disposed in the LDPC information bits.

A new bit-level permutation image encryption algorithm

Abstract: A new chaotic, permutation-substitution architecture based, image encryption algorithm is introduced in this paper. In order to reduce redundancies of Fridrich's structure based image encryption scheme, a novel inter-intra bit-level permutation based confusion strategy is appealed. By means of the proposed confusion stage, statistical properties of the image produced at its output are enhanced (that is, the bit distribution of each bit plane is more uniform and correlation between neighboring higher bit planes is reduced). Also, the proposed image cryptosystem takes advantage of Sudoku grids as to ensure a high performance diffusion process and a higher key space as well. Based on the theoretical arguments and the Matlab implementation, the conducted study demonstrates that the proposed images' encryption algorithm has a desirable level of security.

Circuit and method for dac mismatch error detection and correction in an adc

Abstract: A method comprises sampling an input voltage signal, comparing the sampled input voltage signal with an output signal of a feedback DAC, and determining an (N+1) bit code representation for a comparison result, the (N+1) bit code yielding the N bit output signal. On detection of the (N+1) bit code being equal to a predefined calibration trigger code, performing a calibration for a most significant bit of the (N+1) bit code by replacing the (N+1) bit code by an alternative (N+1) bit code that yields the same N bit output signal, performing an additional comparison cycle using the alternative (N+1) bit code, determining, using comparison results of the additional comparison cycle and the preceding (N+1) th cycle, a sign of a DAC capacitor mismatch error, and tuning programmable binary scaled calibration capacitors in parallel to a capacitor corresponding to the one of the most significant bits of the (N+1) bit code.

Signal field encoding in a high efficiency wireless local area network (WLAN) data unit

Abstract: In a method of generating a field of a physical layer (PHY) preamble of a data unit, information bits to be included in the field are generated. Respective sets of tail bits are appended after respective sets of information bits corresponding to respective ones of a plurality of groups of subfields of the field, each group including one or more of the subfields of the field, to generate an encoder input bit stream. One or more padding bits are added to the encoder input stream to generate a padded encoder input bit stream, the one or more padding bits to ensure an integer number of puncturing blocks in an encoded output bit stream. The padded encoder input bit stream is encoded to generate the encoded output bit stream. The field is generated to include at least some bits from the encoded output bit stream.

Quanta image sensor: concepts and progress

Abstract: The QIS was conceived when contemplating shrinking pixel sizes and storage capacities, and the steady increase in digital processing power. In the single-bit QIS, the output of each field is a binary bit plane, where each bit represents the presence or absence of at least one photoelectron in a photodetector. A series of bit planes is generated through high-speed readout, and a kernel or “cubicle” of bits (x,y,t) is used to create a single output image pixel. The size of the cubicle can be adjusted post-acquisition to optimize image quality. The specialized sub-diffraction-limit photodetectors in the QIS are referred to as “jots” and a QIS may have a gigajot or more, read out at 1000 fps, for a data rate exceeding 1Tb/s. Basically, we are trying to count photons as they arrive at the sensor. This paper reviews the Quanta Image Sensor (QIS) concept and its imaging characteristics. Recent progress towards realizing the QIS for commercial and scientific purposes is discussed. The QIS represents a possible major paradigm shift in image capture.

High Capacity Image Steganography using Adjunctive Numerical Representations with Multiple Bit-Plane Decomposition Methods

Abstract: LSB steganography is a one of the most widely used methods for implementing covert data channels in image file exchanges [1][2]. The low computational complexity and implementation simplicity of the algorithm are significant factors for its popularity with the primary reason being low image distortion. Many attempts have been made to increase the embedding capacity of LSB algorithms by expanding into the second or third binary layers of the image while maintaining a low probability of detection with minimal distortive effects [2][3][4]. In this paper, we introduce an advanced technique for covertly embedding data within images using redundant number system decomposition over non-standard digital bit planes. Both grayscale and bit-mapped images are equally effective as cover files. It will be shown that this unique steganography method has minimal visual distortive affects while also preserving the cover file statistics, making it less susceptible to most general steganography detection algorithms.

Face and palmprint multimodal biometric system based on bit-plane decomposition approach

Abstract: Bit-plane decomposition approach has been introduced \ate\y for single trait biometric system such as face, palmprint, and fingerprint recognition. This approach is able to provide promising high performance rate while reducing the data dimensionality. However, this approach has not been tested on multimodal biometric system which uses more than one biometric trait. Hence, this paper introduces a new multimodal biometric system based on face and palmprint fusion with bit-plane decomposition approach. Pixel level fusion is applied by using simple averaging method before bit-plane feature extraction. Principal Component Analysis is also used on the hybrid face-palm bit planes for further dimension reduction before being classified by Feedforward Backpropagation Neural Network. The experimental results show that the proposed system is able to provide high recognition rate.

Lossy Image Compression Using Multiwavelet Transform for Wireless Transmission

Abstract: The performance of the wavelets within the field of image process is standard. Multiwavelets is the next step in riffle theory and it takes the performance of wavelets to the next level. In this work the performance of the Integer Multiwavelet transform (IMWT) for lossy compression has been studied. The Proposed IMWT shows sensible performance in lossy reconstruction of the images than that of Existing lossy reconstruction. This work utilizes the performance of the Proposed IMWT for lossy compression of images with encoding techniques like Magnitude set coding and Run Length Encoding. The transform coefficients are unit coded by means of Magnitude set coding and run length coding techniques which in turn results with low bits. The transform coefficient matrix is coded on not taking under consideration of the sign values using the Magnitude Set--Variable Length Integer illustration. The sign data of the coefficients is coded as bit plane with zero thresholds. This Bit plane may be used as it is or coded to scale back the bits per pixels. The Simulation was exhausted using Matlab.

Robust lossless digital watermarking using integer transform with Bit plane manipulation

Abstract: In this paper, a robust lossless digital watermarking scheme based on a generalized integer transform in spatial domain is proposed. In the proposed method, data bits are hidden into the cover media by a reversible generalized integer transform with bit plane manipulation. With the reversible transform, data can be hidden in the cover media, and the stego media can be restored to its original form after extraction of the hidden data. In embedding procedure, adaptive bit plane manipulation is applied to increase robustness of the algorithm while keeps good visual quality. To further increase the robustness of the algorithm, we repeatedly embed watermark bits and use majority voting to decode the hidden information in extraction procedure. Furthermore, a threshold is introduced in the algorithm, which helps in choosing regions that would result lower variance for embedding, as regions with lower variance is more robust against JPEG compression. The proposed scheme is quite different from the existing robust lossless data hiding algorithms which are histogram-based. The performance of the proposed scheme is evaluated and compared with state-of-the-arts techniques respect to robustness, data payload capacity and peak signal-to-noise ratio (PSNR). In the experiments, the proposed method can embed more than 10000 bits into 512 by 512 grayscale and medical images, and has around 30 dB in PSNR. In case of small watermark with 100 bits, marked images can have PSNR above 60 dB and with 0.1 bpp in JPEG robustness in the best cases. Conclusively, the robustness of the proposed method is quite good, and the results of hiding capacity and imperceptibility are also satisfactory.

Analysis of bit-plane images by using principal component on face and palmprint database

Abstract: The bit-plane feature extraction approach has lately been introduced for face and palm-print recognition. This approach decomposes an 8-bit grey level image into eight groups of bit layers. The assumption of this approach is that the highest order of a bit-plane decomposition, which has the most significant bits of all pixels, contains the most biometric features. Nonetheless, most research has identified bit-plane images illustratively. Hence, in order to endorse the assumption, we performed an analysis on face and palm-print images to identify the bit-plane that contributes most significantly to the recognition performance. Analysis was done based on Principal Component Analysis (PCA). The first principal component was applied as it is defined for the largest possible variance of the data. Next, Euclidean distance was calculated for matching performance. It was observed that bit-plane 6 and 7 contributed significantly to recognition performance. © 2016 Universiti Putra Malaysia Press.

Conversion schemes for cryptography systems

Abstract: In a general aspect, a conversion scheme is used with a cryptographic system. In some aspects, a pad bit vector is generated based on a size of a message bit vector, and a record bit vector is generated based on the pad bit vector. The record bit vector indicates the size of the pad bit vector. The record bit vector, the message bit vector, and the pad bit vector are combined to yield a first bit vector. A hash function is applied to the first bit vector, and an encryption function is applied to a portion of the first bit vector. A ciphertext is generated based on the output of the hash function and the output of the encryption function.

Bit vector search index using shards

Abstract: The technology described herein provides a bit vector search index for a search system that uses shards. The bit vector search index comprises a data structure for indexing data about terms from a corpus of documents. The data structure includes a number of bit vectors. Each bit vector comprises an array of bits and corresponds to a different set of terms. Bits in the bit vector are used to represent whether at least one document corresponding to the bit includes at least one term from the set of terms corresponding to the bit vector. The search index is provided in a number of shards. Each shard corresponds to a subset of documents having documents lengths within particular a range of document lengths.

Delta-sigma digital radiometric system

Abstract: A passive radiometric system for thermally imaging objects in a scene. The system includes a digital square-law quantizer circuit including a plurality of comparators and a voltage divider network having a plurality of resistors. Each comparator receives a different reference signal generated by the voltage divider network and a common power signal from an antenna and outputs a high or low digital bit signal. The system also includes a delta-sigma circuit having a weighting table responsive to the digital bit signals from the comparators that converts the digital bit signals to a normalized bit word. The delta-sigma circuit also includes an accumulator that receives the digital bit words from the weighting table and provides an average of the digital bit words. The system also includes a digital-to-analog converter that converts the averaged bit words to an analog signal that is provided as a feedback signal to the quantizer circuit.

A quality-on-demand electrocardiogram signal compression using modified set partitioning in hierarchical tree

Abstract: Biomedical signals enfold much crucial clinical information. Cardiac imperfection includes information on the morphology of its electrical signals. These signals are classically recorded over a considerable period, so the size of data file becomes bulky and hence compression is essential. This paper focuses on the implementation of electrocardiogram signal compression using wavelet-based progressive coding such as set partitioning in hierarchical tree and its modified version to achieve improvement in the speed at low bit rate. We obtained compression ratio up to 22:1 for MIT-BIH arrhythmia database record number 117 with a percent mean square difference of 0.9 and 0.73 % using orthogonal and biorthogonal wavelets, respectively. The coders accomplish bit rate control and produce a bit stream that is progressive in quality. It facilitates the user to trim the bit stream at desired point and make required quality restoration for the reduced file size with user-defined compression ratio or bit rate.

Storage and retrieval of data from a bit vector search index

Abstract: The technology described herein provides for storing and retrieving data in a bit vector search index. The bit vector search index stores data about terms from documents using bit vectors. Each bit vector comprises an array of bits and corresponds to a different set of terms. Each bit in the bit vector is used to represent whether a document includes at least one term from the set of terms. A band table is used to store bit vector configurations for bands of terms having similar term characteristics. Each term is indexed in the bit vector search index according to a bit vector configuration for a band to which it belongs. When identifying bit vector storage locations for terms, explicit mappings are used for some terms and ad hoc approaches used for other terms. Explicit mappings provide specific locations for terms, while ad hoc approaches use mapping algorithms assigned to bands.

Transform block coding

Abstract: Transform block coding is performed very efficiently in terms of computational complexity and compression ratio, by coding the magnitude bits of the transform coefficients distributed in a matrix, in which the magnitude bits of the spectral coefficients are arranged column-wise with the spectral coefficients of the transform block ordered along a row direction of the matrix That is, magnitude bits within a certain column of the matrix belong to a certain spectral coefficient, while magnitude bits within a certain row of the matrix belong to a certain bit plane In this configuration, the distribution of non-zero magnitude bits may be condensed towards one corner of the matrix, corresponding to, for instance, the least significant bit plane and corresponding to, by using a scan order among the transform coefficients which sorts the transform coefficients generally in a manner from lowest to highest frequency, the lowest frequency Various low complexity variants are presented

Computer-readable recording medium, encoding apparatus, and encoding method

Abstract: An encoding apparatus detects a bit repeating portion in a mantissa part bit string. The mantissa part bit string is a part of a bit string of a floating point number and corresponds to a mantissa of the floating point number. The floating point number has a sign, an exponent, and the mantissa. The bit repeating portion includes repetitions of a particular bit pattern up to a tail of the mantissa part bit string. The encoding apparatus encodes the bit string of the floating point number into a converted bit string with a first part bit string and a second part bit string. The first part bit string includes a sign part bit string, an exponent part bit string, and a part of the mantissa part bit string that exclude a bit string portion after a secondary repetition of the particular bit pattern. The second part bit string specifies the particular bit pattern in the first part bit string.

High Capacity Image Steganography Using Adjunctive Numerical Representations With Multiple Bit-Plane Decomposition Methods

Abstract: LSB steganography is a one of the most widely used methods for implementing covert data channels in image file exchanges [1][2]. The low computational complexity and implementation simplicity of the algorithm are significant factors for its popularity with the primary reason being low image distortion. Many attempts have been made to increase the embedding capacity of LSB algorithms by expanding into the second or third binary layers of the image while maintaining a low probability of detection with minimal distortive effects [2][3][4]. In this paper, we introduce an advanced technique for covertly embedding data within images using redundant number system decomposition over non-standard digital bit planes. Both grayscale and bit-mapped images are equally effective as cover files. It will be shown that this unique steganography method has minimal visual distortive affects while also preserving the cover file statistics, making it less susceptible to most general steganography detection algorithms.

Performance improvement of LSB-based steganalysis using bit-plane decomposition of images

Abstract: In this paper, we present an improved least significant bit (LSB)-based steganalysis scheme using the bit-plane decomposition of images. We derive a mathematical condition that can enhance the detection rate for hidden messages based on the correlation coefficient between two parts of a decomposed image. Based on this condition, images are classified and segregated into two groups: the full image including all of the bit-planes and a sub-image containing only the lower bit-planes. The feature vectors for steganalysis are extracted independently form each group. Three types of conventional feature vectors were extracted to verify our proposed method and experiments demonstrated that conventional steganalysis schemes exhibited improved performance using our proposed method. In conclusion, our scheme can be used as a general steganalyzer regardless of the specific steganalysis methods employed for LSB-based steganalysis.

Difference Expansion Based Robust Reversible Watermarking with Region Filtering

Abstract: Existing robust reversible watermarking methods usually have poor visual quality or unstable robustness and reversibility, implies that reversibility cannot be assured even in lossless channel In this paper, a novel robust reversible watermarking method is proposed In the proposed method, bit plane manipulation is applied to hide watermark bits in bit planes that are lesser affected by attacks Region filtering is also adopted to find blocks that result in low variance for watermark embedding to further increase its robustness Experimental results show that our method has improved performances compared with state-of-the-art technology, better surviving bit rate, a robustness measure, is obtained in the proposed algorithm

Wavelet domain distributed multi-view video coding based on layered WZ frame

Abstract: The invention provides a wavelet domain distributed multi-view video coding scheme based on a layered WZ frame. At a coding end, traditional intra-frame coding and decoding are carried out on a K frame; after N-layer discrete wavelet transform is carried out on the WZ frame, quantification, bit plane extraction and channel coding are carried out. At a decoding end, according to the scheme, the motion characteristic of a video sequence is taken into full consideration; an edge information prediction structure based on the layered WZ frame is provided; initial edge information of a current layer of video frames is obtained by carrying out MCTI through two closest adjacent decoded frames of a higher lever layer. When decoding is carried out, motion vectors and edge information with higher and higher quality are updated step by step from low-resolution images to high-resolution images according to the forward and backward reference frames of a current frame and the generated initial edge information, thereby realizing iterative decoding. An experimental result shows that compared with a traditional wavelet domain DMVC system, the scheme has the advantages that the quality of the generated edge information is better, and the RD performance of the DMVC system is improved.

An Image Segmentation Algorithm Based on Gray Bit Plane for Flame

Abstract: Flame region judgment is an important part of fire detection system; meanwhile the flame of intelligent monitoring system also has important practical significance to national fire control safety. Therefore, this article puts forward the flame image segmentation method based on gray level bit plane. Firstly, by studying the distribution of flame image in OHTA color space, we found that it can accurately segment the flame area by using the method of the gray level bit plane for component image in OHTA color space. The experiments results show that the algorithm in different scenarios for segmenting flame has a good effectiveness and robustness.