Photo retouching aims to adjust the hue, luminance, contrast, and saturation of the image to make it more human and aesthetically desirable. Based on researches on image imaging process and artists' retouching processes, we propose three improvements to existing automatic retouching methods. Firstly, in the past retouching methods, all the imaging conditions in EXIF were ignored. According to this, we design a simple module to introduce these imaging conditions into a network called ECM (EXIF Condition Module). This module can improve the performance of several existing auto-retouching methods with only a small parameter cost. Additionally, artists' operations also were ignored. By investigating artists' operations in retouching, we propose a two-stage network that brightens images first and then enriches them in the chrominance plane to mimic artists. Finally, we find that there is a color imbalance in the existing retouching dataset, thus, hue palette loss is designed to resolve the imbalance and make the image more vibrant. Experimental results show that our method is effective on the benchmark MIT-Adobe FiveK dataset and PPR10 K dataset, and achieves SOTA performance in both quantitative and qualitative evaluation.

In this paper, we present Point Cloud Color Constancy, in short PCCC, an illumination chromaticity estimation algorithm exploiting a point cloud. We leverage the depth information captured by the time-of-flight (ToF) sensor mounted rigidly with the RGB sensor, and form a 6D cloud where each point contains the coordinates and RGB intensities, noted as (x,y,z, r,g, b). PCCC applies the PointNet architecture to the color constancy problem, deriving the illumination vector point-wise and then making a global decision about the global illumination chromaticity. On two popular RGB-D datasets, which we extend with illumination information, as well as on a novel benchmark, PCCC obtains lower error than the state-of-the-art algorithms. Our method is simple andfast, requiring merely 16 x 16-size input and reaching speed over 140 fps (CPU time), including the cost of building the point cloud and net inference.

Illumination estimation refers to estimating the chromaticity vector of illumination, and can be used to recover the surface color under white light. Dual-illuminant is a common scenario in computational illumination estimation tasks. A straightforward way to correct the dual-illuminant image can be estimating a spatially-varying illumination map. However, it is hindered by the lack of large-scale annotated datasets for data-driven methods. In this paper, we propose a novel approach to obtain the dominant dual-illuminant and the pixel-wise illuminant map on real dual-illuminant raw images. Our method consists of 1) dual-illuminant image generator (DIG) to synthesize dual-illuminant images from unique-illuminant datasets assuming the Lambertian model; 2) dual-illuminant estimation network (DE-Net) to estimate illuminant both globally and locally. Quantitative experiments show that with DIG synthesized dual-illuminant images, DE-Net obtains the best accuracy in dual-illumination detection and estimation on the Gehalr-shi dataset and Mutlti-Illuminant Multi-Object dataset.

In Bayesian theory, the maximum posterior estimator uses prior information to estimate the noise in the machine learning model by adding the regularization term. The regularization terms L1and L2correspond to Laplacian prior and Guassian prior, respectively. In existing deep learning models, in order to use the gradient descent optimization algorithm and achieve good results, most models take L2regularization as the regularization term of the network model to fit the complex Guassian noise. However in practice, the Laplace noise and the Guassian noise are both considered as data noise. For multi-layer perceptrons, the difficulty caused by adding L1and L2into the optimization function of the network is solved by proposing an ensemble model for error modeling through adopting the divide and conquer strategy. First, several base learners are trained to fit different noise distributions of data, then the final results can be obtained by taking the results of each base leaner as new data to train a meta leaner, and get the final results. Among them, coordinate regression method is used to solve L1loss, while the pseudo-inverse learning algorithm is employed to solve L2loss. Both methods are nongradient optimization algorithms. The comparison results of the model on several data sets show that the proposed ensemble model achieves better performance.

Pulsars search has always been one of the most concerned problem in the field of astronomy. Nowadays, with the development of astronomical instruments and observation technology, the amount of data is getting bigger and bigger. Radio pulsar surveys have generated and will generate vast amounts of data. To handle big data, developing new technologies and frameworks to efficiently and accurately analyze these data become increasing urgent. The number of positive and negative samples in pulsar candidate data set is very unbalanced, if we only use these a few positive samples to train a deep neural network (DNN), the trained DNN is prone because of the problem of overfitting and will affect the generalization ability. Motivated by the mixtures of experts network architecture, we proposed a hierarchical model for pulsar candidate selection which assembles a set of trained base classifiers. Moreover, training a neural network always takes a lot of time because of using gradient descent (GD) based algorithm. In this work, we utilize the pseudoinverse learning algorithm instead of GD based algorithm to train proposed model. With the designed network architecture and adopted training algorithm, our model has the advantages not only with high steady-state precision but also good generalization performance.