IET Image Processing

Image denoising is still a challenging problem in image processing. The authors propose a novel image denoising method based on a deep convolution neural network (DCNN). Different from other learning-based methods, the authors design a DCNN to achieve the noise image. Thus, the latent clear image can be achieved by separating the noise image from the contaminated image. At the training stage, the ... View full abstract»

A hyperspectral anomaly detector, which uses the benefits of a proposed background feature extraction method and the kernel trick, is introduced in this study. The proposed method is differential image based detector (DID). The DID method uses the differential image to estimate the variations of background in the feature extraction phase. The proposed feature extraction method slows the variations... View full abstract»

Face recognition technique has obtained great progress and excellent results on public data sets. However, traditional algorithms suffer from various changes such as illumination, expression, and misalignment in practical applications. To solve these problems, this study proposes a novel face recognition algorithm simultaneously resolves these challenges. The key idea is reducing the influence of ... View full abstract»

This study presents an adaptive image segmentation method based on the fuzzy c-means with spatial information (FCM_S). First, the advantages of the local FCM_S over the global FCM_S and its segmentation characteristics are introduced, on the basis of which, the accumulated local FCM_S is proposed to classify each pixel in an image by using information from different local windows that contain them... View full abstract»

Convolutional neural network (CNN) has proven to be a highly efficient approach to face recognition. In this study, the authors introduce a new layer to embed the patch strategy in convolutional architectures to improve the effectiveness of face representation. Meanwhile, a multi-branch CNN is constructed to learn features of each cropped patch by the patch strategy and then fuses all the patch fe... View full abstract»

As a weakly supervised learning technique, multiple instance learning (MIL) has shown an advantage over supervised learning methods for automatic detection of diabetic retinopathy (DR): only the image-level annotation is needed to achieve both detection of DR images and DR lesions, making more graded and de-identified retinal images available for learning. However, the performance of existing stud... View full abstract»

Automatic extraction of retinal blood vessels plays an important role in the diagnosis of many retinal diseases and also for diagnosing several complicated diseases such as stroke, hypertension and cardiovascular diseases. Due to the complex nature of retinal vessel network, the manual segmentation of vessels is a tedious task which also requires high training and skills. This study presents a new... View full abstract»

The impact of radiation dose is directly related to the quality of computed tomography (CT) images. Low-dose CT images are degraded with the noise and other factors. Noise reduction methods are very helpful to enhance the noisy CT images with a possibility to increase the signal-to-noise ratio (SNR) and have a scope for further reduction of radiation dose. In this study, a denoising scheme is prop... View full abstract»

The authors propose a new single image dehazing method. Different from image restoration and image enhancement method, their method is based on the idea of image fusion. Image dehazing is to remove the influence of the haze between the scene and the camera. First, combined with the depth information, the haze layer is subtracted in the hazy image to improve the colour saturation, which produces th... View full abstract»

The major drawback of the fuzzy c-means (FCM) algorithm is its sensitivity to noise. The authors propose a new extended FCM algorithm based a non-parametric Bayesian estimation in the wavelet transform domain for segmenting noisy MR brain images. They use the Bayesian estimator to process the noisy wavelet coefficients. Before segmentation based on FCM algorithm, they use an a priori statistical m... View full abstract»

Over the past decade, much research has been done to improve single-fog images. However, most of these have concentrated on outdoor environments and little has been done for indoor environments. In this study, an effective method of removing fog from images both indoors and outdoors is presented. A new single image enhancement approach is based on mixture of dark channel prior (DCP) and contrast l... View full abstract»

High-efficiency video coding (HEVC) is an international video coding standard. It can reduce bit rate by almost 50% when preceding state-of-the-art standard H.264/advanced video coding (AVC) with the same objective quality but increase about 40% encoding complexity. The computation complexity of HEVC largely relies on the inter-prediction, which consumes about 60-70% of the total encoding time. Th... View full abstract»

The fusion of multimodal medical information is considered as an assisted approach for the medical professionals. Computed tomography and magnetic resonance (CT-MR) medical image fusion are able to help the radiologist in precise diagnosis of disease and deciding the required treatment in accord with the patient's condition. Therefore, a cascaded framework is proposed in this study that presents a... View full abstract»

Pulse-coupled neural network (PCNN) is a biologically-inspired algorithm suited for image processing. However, determining a set of parameters involved in the alteration of the neural behaviour remains a prevalent research for further application. To apply the model into image segmentation, this study proposes an extended PCNN model by using a strategy of the decision tree, and establishes links b... View full abstract»

With the advancement of image editing tools in today's world, the manipulation of images like cropping, cloning, resizing, etc., becomes an easy proposition and on the other end, checking or determining whether an image has been manipulated or not, becomes a great challenge. Copy-move forgery in images is the most popular tampering method in which a portion of an image is copied and pasted in some... View full abstract»

The author introduces a contour detection method that has relatively low complexity yet still highly accurate. The method is based on extrema detection along the four principal orientations, a trick that can be used to detect not only edges but, in particular, also ridges and rivers. The author makes a comparison to the popular Canny algorithm and shows that the proposed method's only downside is ... View full abstract»

Perceptual quality assessment of stereoscopic images is a challenge in three-dimensional video systems. Existing studies suggest that simply averaging the quality of left and right views can effectively predict the quality of symmetrically distorted stereoscopic images, but prediction deviation occurs in the case of asymmetrically distorted stereoscopic images. Most previous stereoscopic image qua... View full abstract»

Colourisation is a process of adding colour to greyscale images. In this study, the authors propose two new colourisation models based on non-local total variation regularisation in the chromaticity and brightness (CB) colour space and the YIQ colour space. Lagrange multiplier method is used to handle the sphere constraint of chromaticity in the CB colour space. By introducing an extra variable an... View full abstract»

Printed circuit board wire segmentation based on computed tomography (CT) image can help subsequently locate and estimate inner faults of circuit in an automatic and non-destructive manner. However, CT imaging is prone to suffer from scattered artefacts, metal artefacts and other interference, destroying compact boundary structures of wires. Wires have the characteristic of dense local distributio... View full abstract»

License plate recognition (LPR) system plays a vital role in security applications which include road traffic monitoring, street activity monitoring, identification of potential threats, and so on. Numerous methods were adopted for LPR but still, there is enough space for a single standard approach which can be able to deal with all sorts of problems such as light variations, occlusion, and multi-... View full abstract»

The second generation bandelet transform uses the two-dimensional (2D) separable wavelet transform to improve its image denoising and compression performance. However, the 2D separable wavelet transform is not a shift-invariant transform and therefore cannot capture geometric information well. The authors propose a hybrid image denoising method in which the 2D separable wavelet transform in the se... View full abstract»

A novel chaos-based colour image encryption algorithm is proposed, which adopts a one-time key mechanism based on message-digest algorithm 5 (MD5) value of the input plain image. The algorithm combines several key technologies including fractional Fourier transform (FrFT), MD5, and global scrambling. Using fast digital discrete FrFT, the algorithm develops the complex data manipulati... View full abstract»

In this study, a novel normal curvature-induced variational model which involves a higher-order regulariser based on the normal curvature prior information of image surface is proposed for image restoration. Furthermore, the authors derive a preferably equivalent formulation for the proposed normal curvature-induced higher-order regulariser. Then, they design an efficient algorithm to solve the pr... View full abstract»

Fuzzy C-means algorithm is a popular image segmentation algorithm and many researchers in the past have introduced several improved versions of it. However, they still lacked robustness for segmenting key regions of magnetic resonance (MR) human brain transversal images such as white matter, grey matter, and cerebro spinal fluid with an almost similar contouring of the edges. This study highlights... View full abstract»

This study presents an efficient fast bit rate transcoding method for high-efficiency video coding (HEVC) screen content coding (SCC). It utilises the correlation between the current coding unit (CU) and the corresponding decoded CU to skip the normal intra mode or intra block copy mode. Furthermore, quantisation parameter values are also incorporated into the algorithm for better performance. In ... View full abstract»

Steganography is used for secret or covert communication. A graph wavelet transform-based steganography using graph signal processing (GSP) is presented, which results in better visual quality stego image as well as extracted secret image. In the proposed scheme, graph wavelet transforms of both the cover image and transformed secret image (using Arnold cat map) are taken followed by alpha blendin... View full abstract»

Image fidelity refers to the ability of a process to render an image accurately. As image enhancement algorithms have been developed in recent years, how to assess the performances of different image enhancement algorithms has become an important question. Some objective image quality assessment (IQA) methods have been proposed, but there is little research on the image fidelity evaluation when co... View full abstract»

Images degraded by haze usually have low contrast and fide colours, and thus have bad effects on applications such as object tracking, face recognition, and intelligent surveillance. So the purpose of dehazing is to recover the image contrast without colour distortion. The dark channel prior (DCP) is widely used in the field of haze removal because of its simplicity and effectiveness. However, whe... View full abstract»

In this study, a novel underwater colour image enhancement approach based on hue preserving is presented by combining hue-saturation-intensity (HSI) and HS-value (HSV) colour models. In this study, the proposed wavelet-domain filtering (WDF) and constrained histogram stretching (CHS) algorithms are operated on HSI and HSV colour models, respectively. The degraded image is first converted from red-... View full abstract»

This study proposes a local similarity refinement strategy to handle the parallax problem in image stitching. The proposed method is combined with deconvolution to acquire high-accuracy matching between corresponding source images. Shape-preserving half-projective warp was used to eliminate distortion across the non-overlapping region caused by the global projective transformation. The proposed re... View full abstract»

The analysis of retinal vascular is quite important because many diseases including stroke, diabetic retinopathy (DR) and coronary heart diseases can damage retinal vessel structure. In this research, a technique has been proposed using a combination of pre-processing steps, vessel enhancement techniques, segmentation and post-processing. The pre-processing section comprises of adaptive histogram ... View full abstract»

Line detection in handwritten documents is an important problem for processing of scanned documents. While existing approaches mainly use hand-designed features or heuristic rules to estimate the location of text lines, the authors present a novel approach that trains a fully convolutional network (FCN) to predict text line structure in document images. A rough estimation of text line, or a line m... View full abstract»

Cancer tissues in mammography images exhibit abnormal regions; it is of great clinical importance to label a mammography image as having cancerous regions or not, perform the corresponding image segmentation. However, the detailed annotation of the cancer region is often an ambiguous and challenging task. The authors describe a fully automatic computer-aided detection and diagnosis (CAD) system to... View full abstract»

A novel fusion algorithm based on guided filter (GF) for computed tomography (CT) and magnetic resonance imaging (MRI) medical images is proposed. In this algorithm: approximation coefficient and three wavelet coefficients of CT and MRI are obtained by the wavelet transform, respectively. Two weight maps are obtained by comparison of the pixel values of the two approximation coefficients. A GF is ... View full abstract»

The authors introduce an edge detection and recovery framework based on open active contour models (snakelets) to mitigate the problem of noisy or broken edges produced by classical edge detection algorithms, like Canny. The idea is to utilise the local continuity and smoothness cues provided by strong edges and grow them to recover the missing edges. This way, the strong edges are used to recover... View full abstract»

Pedestrian detection has become one of the hottest topics in intelligent traffic system because of its potential applications in driver assistance and automatic driving. In this study, a fast pedestrian detection and dynamic tracking method within vehicle-to-vehicle (V2V) cooperative environment is proposed. A dynamic tracking-by-detection framework for real-time pedestrian detection is developed.... View full abstract»

Here, a hybrid feature descriptor-based method is proposed to recognise human emotions from their facial expressions. A combination of spatial bag of features (SBoFs) with spatial scale-invariant feature transform (SBoF-SSIFT), and SBoFs with spatial speeded up robust transform are utilised to improve the ability to recognise facial expressions. For classification of emotions, K-nearest nei... View full abstract»

Most applications in computer vision manage to suppress textures and noise while maintaining meaningful structure based on colour intensity variation, but it is intractable due to texture patterns or error. This study presents an edge-preserving suppression method for depth estimation. The authors formulate a functional energy function based on the relative total intensity and space variation, and... View full abstract»

Automatic assessment of retinal vessels plays an important role in the diagnosis of various eye, as well as systemic diseases. A public screening is highly desirable for prompt and effective treatment, since such diseases need to be diagnosed at an early stage. Automated and accurate segmentation of the retinal blood vessel tree is one of the challenging tasks in the computer-aided analysis of fun... View full abstract»

Sobriety test, which commonly uses a breathalyser for estimating blood alcohol content (BAC) from a breath sample, is commonly used to detect drunk driving. The detection often gives rise to sanitary concern and violation of human right. This research proposes a new method that employs non-invasive measurement of photoplethysmography (PPG) signal for detecting BAC of the test subject under the sob... View full abstract»

In this study, the perceptual video quality (PVQ) for the vogue 360-degree video with compression artefacts viewed on the visual reality (VR) head-mounted display (HMD) is obtained for the first time by an elaborately designed subjective experiment. The characteristic of the PVQ of omnidirectional (360-degree) video on the VR HMD and PC monitor is then investigated. The PVQ on the HMD is found to ... View full abstract»

With the rapid development of computer science, problems with digital products piracy and copyright dispute become more serious; therefore, it is an urgent task to find solutions for these problems. In this study, the authors' develop a digital watermarking algorithm based on a fractal encoding method and the discrete cosine transform (DCT). The proposed method combines fractal encoding method and... View full abstract»

The popular histogram equalisation (HE) technique, which was developed to improve the image contrast, sometimes may also be misused to hide intensity variations in tampered images with ill intention. The authors investigate how existing image forensic techniques may fail to detect HE operation in highly compressed and low-resolution images. They then propose an algorithm to detect whether a given ... View full abstract»

To overcome the drawbacks of existing filters for salt and pepper noises, an adaptive probability filter is proposed. For an image, it detects salt and pepper noises based on the characteristic of minimum and maximum intensity values of the images, as well as the distribution of noise. If the noise-free intensities in neighbourhood repeat with a certain probability, the noise-free intensity with h... View full abstract»

This study is based on improving the visual quality of the images captured under different illumination conditions, i.e. overexposed and underexposed. This study presents a fuzzy image enhancement process based on a finite fuzzy set which is defined to optimise entropy, noise, intensity and edge information. In the proposed fuzzy approach, the overexposed and underexposed images are mapped to form... View full abstract»

Star images obtained by star sensors have a low signal-to-noise ratio due to various physical constraints. Low resolution also causes stellar centroid extraction error when traditional methods such as the Gaussian filter or adaptive median filter are utilised to de-noise star images. An automatic centroid extraction method for noisy low-resolution star images is proposed in this study. First, spar... View full abstract»

Estimating the three-dimensional (3D) motion from sparse laser point clouds is a highly challenging endeavour facing computer and robotic vision engineers. In this study, a novel method is proposed for robustly estimating the scene flow from a laser scanner assisted by a camera. Conditional random field (CRF) is constructed by a spatial structure of point clouds, the energy of which is minimised b... View full abstract»

A cubic trigonometric B-spline representation with two parameters is constructed in this work. A soft computing technique, genetic algorithm, is used to find the optimal value of the parameters in the description of B-spline so that the sum square error is minimised. The newly constructed B-spline is then utilised to interpolate two-dimensional digital images. The image quality metrics peak signal... View full abstract»

For many image fusion problems, the most used technique is selecting features with rich information. The robust image fusion method based on block compressive sensing principle is studied here. Compressive sensing is known to provide an effective method with high accuracy. The framework of the proposed method is given in various perspectives: block sparse representations, restoration algorithms, f... View full abstract»

This paper automatizes the process of bone age maturity assessment by applying three versions of particle swarm optimization (PSO) along with image processing methods to the left hand X-ray images. PSO versions were adopted to enhance the segmentation accuracy. The proposed method was compared to the conventional visual inspection method in terms of three segmentation criteria, classification accu... View full abstract»