Abstract: Gradient estimators are mostly designed to yield accurate and robust estimates of the gradient magnitude, not the gradient direction. This paper proposes a method for the accurate and robust estimation of both the gradient magnitude and direction. It robustly estimates the gradient in the x- and y-directions. The robustness against noise is achieved by prefiltering and postfiltering of the gradient in each direction. To reduce edge blurring effects introduced by these filters, the gradient in a certain direction is obtained by applying the prefilter and postfilter in the perpendicular direction. The basic elements employed in each window are: highpass, lowpass and aggregation operators. The highpass operator is used as a gradient estimator, the lowpass operator is for prefiltering and postfiltering, and the aggregation operator is for aggregating the prefiltered and postfiltered gradients. Four different combinations of highpass, lowpass and aggregation operators are proposed: MVD-Median-Mean, MVD-Median-Max, RCMG-Median-Mean, and RCMG-Median-Max. Experimental results show that the RCMG-Median-Mean has the best performance in estimating the gradient and detecting the edges in noisy color images. It is computationally more efficient than the state-of-the-art gradient estimators and is able to accurately estimate the gradient direction as well as the gradient magnitude. Computer simulation results show that the proposed method outperforms other recently proposed color gradient estimators and edge detectors.

Abstract: According to the color yarns in the fabric, the yarn-dyed fabrics are divided into two categories: single-systemmelange color fabrics and double-system-melange color fabrics. The method for inspecting the density of double-systemmelange color fabrics is discussed in this study. By analyzing the pattern and color characters of double-system-melange color fabrics, color-gradient image is proposed to detect the density. The gray-projection method and correlation coefficient method are selected to locate the wefts and warps. With the help of Fourier low-pass filter, the positions of yarns in double-system-melange color fabric are found, and then the density can be obtained by counting the yarns in a unit length automatically. The experiment proved that the method proposed can detect double-system-melange color fabric density successfully.

Abstract: Conventional objects extraction method are not efficient for color document image with large graphics. For example, the projection profile and connected component based methods scanning the large graphics many times. To display the large graphics are extracted, conventional methods use rectangle to represent it. Thus, scanning into the large graphics is time-consuming. In this paper, a novel system for efficiently analyzing color documents is proposed to solve above mentioned problem. The proposed system includes color transformation, background color determination, objects extraction by top-down method, and objects classification without parameters. The proposed color document analysis system is efficient because it scans only background pixels such that the temporal complexity is O (NB), where NB is the total number of background color pixels. Results of this study demonstrate that this system is more effective and efficient than other methods. Moreover, the proposed algorithm can be run in an embedded environment (such as a mobile device) and processed in real-time system due to its simplicity and efficiency.

Abstract: Some embodiments provide a computer program for matching colors of a first image to colors of a second image. The computer program identifies a set of transforms for converting the first image to a device-independent color space. The computer program modifies the set of transforms to segment colors of the first image into a set of segmented colors. The computer program applies the modified set of transforms to pixel values of the first image in order to segment the pixels of the first image into the set of segmented colors. The computer program applies the modified set of transforms to pixel values of the second image in order to segment the pixels of the second image into the set of segmented colors. The computer program matches each segmented color in the set of segmented colors in the first image to the segmented color in the second image.

Abstract: An applicator having a color gradient. The applicator includes an outer member having a first end, a second end disposed opposite the first end, a longitudinal axis, a length measured along the longitudinal axis, and an exterior surface. The outer member further includes a color gradient extending along at least a portion of the length from a first region to a second region, the color gradient being visible by a user viewing the exterior surface of the outer member.

Abstract: A modified marker-extraction based watershed algorithm was proposed in this paper to deal with the over-segmentation during color image segmentation.The modified algorithm was constituted of smooth filtering,color gradient calculation,marker-extraction and watershed transformation.During smooth filtering,a novel spectrum envelope filter was designed.The new filter had a better performance on edge-preserving which was used to smooth the imported color image and gradient image.The color gradient was calculated right in the color vector space.During the course of marker-extraction,H-minima transformation was used to extract minima-marker in smoothed gradient image firstly,whose parameter was adaptively controlled by the depth information of local minima region.Then,the extracted minima-marker was updated by more information of local minima region.Finally,the updated minima-marker was imposed on the original gradient image to get the marked gradient.The final result was gotten from the watershed transformation on the marked gradient.The experimental results indicate that the modified algorithm overcomes the difficulties in getting accurate edges and detecting weak edges.Furthermore,it has a more reasonable initialization rule of parameters and a better adaptability.

Abstract: Image resampling method using color edge-directed interpolation has been developed. It uses color image gradient to perform the interpolation across image gradient rather than along image gradient. The developed combined method takes color low resolution image and grayscale high resolution image obtained by a non-linear image resampling method as an input. It includes consecutive calculation stages for high resolution color gradient, for high resolution color information interpolation and finally for high resolution color image assembling. The concept of color basic edges is used to analyze the results of color image resampling. Color basic edge points metric was suggested and used to show the effectiveness of the proposed image interpolation method.

Abstract: A multi-wavelength digital holographic (MWDH) system has been developed to record and reconstruct color images In comparison to working with digital cameras, however, high-quality color reproduction is difficult to achieve, because of the imperfections from the light sources, optical components, optical recording devices and recording processes Thus, we face the problem of correcting the colors altered during the digital holographic process We therefore propose a color correction scheme to correct the chromatic distortion caused by the MWDH system The scheme consists of two steps: (1) creating a color correction profile and (2) applying it to the correction of the distorted colors To create the color correction profile, we generate two algorithms: the sequential algorithm and the integrated algorithm The ColorChecker is used to generate the distorted colors and their desired corrected colors The relationship between these two color patches is fixed into a specific mathematical model, the parameters of which are estimated, creating the profile Next, the profile is used to correct the color distortion of images, capturing and preserving the original vibrancy of the reproduced colors for different reconstructed images

Abstract: In this paper, we propose a novel robust vehicle tracking method based on random sampling. Firstly, random sampling and prediction to the random sampling points are performed. Secondly, color gradient feature of object contour combined with template match is used for weighting. Finally the centroid of target is located through summing to the weighted random sampling points. This method needn't too many restrictions, for example a certain hypothesis or requirement to background et al. With the calculating to object contour, too much time is saved. Then, real-time and accurate tracking is achieved in this paper. Experimental results show an important performance gain and better tracking accuracy in favor of our approach.

Abstract: Color line extraction is an important part of the segmentation process. The proposed method is the generalization of the Gradient Line Detector (GLD) to color images. The method relies on the computation of a color gradient field. Existing color gradient are not "oriented": the gradient vector direction is defined up to π, and not up to 2π as it is for a grey-level image. An oriented color gradient which makes use of an ordering of colors is proposed. Although this ordering is arbitrary, the color gradient orientation changes from one to the other side of a line; this change is captured by the GLD. The oriented color gradient is derived from a generalization from scalar to vector: the components of the gradient are defined as a "signed" distance between weighted average colors, the sign being related to their respective order. An efficient averaging method inspired by the Gaussian gradient brings a scale parameter to the line detector. For the distance, the simplest choice is the Euclidean distance, but the best choice depends on the application. As for any feature extraction process, a post-processing is necessary: local maxima should be extracted and linked into curvilinear segments. Some preliminary results using the Euclidean distance are shown on a few images.

Abstract: An encoding method generates an encoded image according to a predetermined encoding format. The method includes the step of, for each block of pixels, determining an average color of colors of the block of pixels in the predetermined color space; selecting at least one luminance line in dependence on an offset in the color space of the average color from the at least one luminance line; identifying a set of candidate base colors lying on the at least one luminance line; and determining, using the set of candidate base colors and the luminance offset values, the set of encoded pixel colors. The base color and the set of luminance offsets are selected in dependence on an encoding error indicative of a sum distance in the color space between the set of encoded pixel colors and the colors of the block of pixels.

Abstract: The invention discloses an injection molding process with a color gradient effect. The injection molding process is realized by the following technical scheme which comprises the following steps of: firstly, transparent resins with colors are selected, and subjected to injection molding by a mold to obtain to a product, wherein the gradient-color part of the injection-molding product is made into a shell with the gradient thickness by the injection-molding mold; and after injection-molding is finished, primers with colors different from an injection-molding object are spayed on the surface of the shell with the gradient thickness of the injection-molding product, and then black primer is sprayed on the surface of the injection-molding product. According to the method provided by the invention, two types of primers are spayed on the surface of the shell with gradient thickness, then the effect of gradient color of the appearance of an injection-molding product can be generated, and different appearance color effects can be generated at different angles.

Abstract: This paper is focused on the characterization of GNSS signals reception environment by estimation of the percentage of visible sky in real-time. On previous works, a new segmentation technique based on a color watershed using an adaptive combination of color and texture information was proposed. This information was represented by two morphological gradients, a classical color gradient and a morphological texture gradient based on mathematical morphology or co-occurrence matrices. The segmented images were then classified into two regions: sky and not-sky. However, this approach has high computational cost and thus, cannot be applied in real-time. On this paper, we present this adaptive segmentation method with a texture gradient calculated by the Gabor filter and a region-tracking method based on a block-matching estimation. This last step reduces the execution time of the application in order to respect the real-time conditions. Since the application works for fish-eye images, a calibration and rectification method is required before tracking and is also presented on this paper. The calibration method presented is based on the straight line condition and thus does not use real word coordinates. This prevents measurement errors. The tracking results are compared to the results of the classification method (which has already been evaluated on previous works). The evaluation shows that the proposed method has a very low error and decreases the execution time by ten times.

Abstract: Image resampling method using color edge-directed interpolation has been developed. It uses color image gradient to perform the interpolation across image gradient rather than along image gradient. The developed combined method takes color low resolution image and grayscale high resolution image obtained by a non-linear image resampling method as an input. It includes consecutive calculation stages for high resolution color gradient, for high resolution color information interpolation and finally for high resolution color image assembling. The concept of color basic edges is used to analyze the results of color image resampling. Color basic edge points metric was suggested and used to show the effectiveness of the proposed image interpolation method.

Abstract: A color correction coefficient generating apparatus includes a first color information obtaining unit that obtains pieces of color information to be corrected in a color space made up of plural color components including a specific color component, a second color information obtaining unit that obtains pieces of color information used for correction corresponding to the pieces of color information to be corrected in the color space, a weighting coefficient obtaining unit that obtains weighting coefficients corresponding to the pieces of color information to be corrected, on the basis of a position relationship between colors represented by the pieces of color information to be corrected and a specified color region and weights that are based on densities of the colors represented by the pieces of color information to be corrected, and a generating unit that generates color correction coefficients for correcting specific density values

Abstract: Displaying visual images by fractional color gradient increments. Distances between adjacent pairs of color shades in a color gradient are scaled down to distances of which the largest is one. The scaled distances are converted into fractions. A largest common denominator of the fractions is determined. The fractions are converted into fractions having the largest common denominator. Numerators of the converted fractions are used to provide samples of the color gradient at intervals of the largest common denominator. A texture is created from the samples. A visual image is displayed on a visual display according to the texture.

Abstract: A technique includes using a processor-based machine to determine a discrete color flow transformation to map target colors of a target object to source colors of a source object based at least in part on a first histogram indicating a color distribution of the target object and a second histogram of a color distribution indicating the source object. The technique includes determining a continuous color flow transformation to map the target colors to the source colors based at least in part on the discrete color flow transformation; and transforming the target colors of the target object to generate a third object based at least in part on the continuous color flow transformation.

Abstract: A color gradient process bar is implemented with Javascript in this paper, and is tested in PHP environment and has been utilized in the real project. From the code demonstrated in this paper, it is easily to extend to create the more complicated and varies visual state process bar though JavaScript, and this realization can directly be referenced in web development