To transfer the color data from a device (video camera) dependent color space into a device? independent color space, a multilayer feedforward network with the error backpropagation (BP) learning rule, was regarded ...To transfer the color data from a device (video camera) dependent color space into a device? independent color space, a multilayer feedforward network with the error backpropagation (BP) learning rule, was regarded as a nonlinear transformer realizing the mapping from the RGB color space to CIELAB color space. A variety of mapping accuracy were obtained with different network structures. BP neural networks can provide a satisfactory mapping accuracy in the field of color space transformation for video cameras.展开更多
A novel single color camera trichromatic mask 3D-PIV technique suitable for measurement of complex flow fields in confined spaces is presented in this paper.By using a trichromatic mask to modulate the imaging optical...A novel single color camera trichromatic mask 3D-PIV technique suitable for measurement of complex flow fields in confined spaces is presented in this paper.By using a trichromatic mask to modulate the imaging optical path of a color camera,the RGB(Red,Green,and Blue)channels of the photosensitive chip were used to record full-frame full-resolution images of tracer particles from three viewing angles.The MLOS-SMART particle reconstruction algorithm was used to obtain three-dimensional particle distribution matrix from particle trichromatic mask images.The impact of parameters such as the inter-hole spacing and hole diameter of the trichromatic mask on the quality of particle reconstruction was analyzed.Through numerical simulation experiments on artificially synthesized three-dimensional flow fields of Gaussian vortex rings,the practicality of this technique in measuring three-dimensional transient velocity fields and the accuracy of velocity measurements were examined.The accuracy and feasibility of the technique are illustrated based on experimental measurements of a zero-net-mass-flux jet.展开更多
An efficient adaptive approximation demosaicking algorithm based on the sampled edge pattern was presented for mosaic images from Bayer color filter array. The proposed algorithm determined edge patterns by four neare...An efficient adaptive approximation demosaicking algorithm based on the sampled edge pattern was presented for mosaic images from Bayer color filter array. The proposed algorithm determined edge patterns by four nearest green values surrounding the green interpolation location. Then according to the edge patterns, different adaptive interpolation steps were applied. Simulations on 12 Kodak photos and 15 IMAX high-quality images showed that the proposed method outperformed the other four demosaicking methods (bilinear, effective color interpolation, Lu's method and Chen's method) for average color peak signal to noise ratios and maintained a relatively low complexity owing to constant color-difference interpolation step and a reasonable terminating condition of iteration.展开更多
The use of Infrared Thermal Scanners proved to be very useful in lots of applications. Using different color palettes, temperatures can be well-represented in the resulting image. However, most color palettes in hot t...The use of Infrared Thermal Scanners proved to be very useful in lots of applications. Using different color palettes, temperatures can be well-represented in the resulting image. However, most color palettes in hot tropical places like the Philippines are unsuitable since the ambient temperature is almost the same as the scanned object or person. This study evaluates twelve (12) known and used color palettes in the market to determine the most suitable for tropical places using the edge/border tracing algorithms Sobel-Feldman and Laplacian. The result shows that color palettes with the most colors produce more noise, making it difficult to distinguish the object scanned from the background. On the other hand, color palettes with three or fewer contrasting colors produce crisp and more detailed results. This study helps developers and researchers efficiently use color combinations suitable for hot weather for an effective thermal scanning and image representation.展开更多
The infrared camera is a curious object for the animals of Changtang.Often covered in camouflage or army green,it looks very"professional".But once I saw the photos they took,I knew the camouflage did not wo...The infrared camera is a curious object for the animals of Changtang.Often covered in camouflage or army green,it looks very"professional".But once I saw the photos they took,I knew the camouflage did not work at all.Most animals could see the cameras without any problem.Some of them showed various degrees of interest in the cameras,while others acted indifferently.To tell the truth,it is not easy to hide something in Changtang.展开更多
为了解决单相机平台受高分辨率与大视场角之间矛盾制约的问题,本文提出了一种大视场、高分辨率、无色差的复眼相机阵列系统。结合人眼视觉成像理论,建立非均匀采样的仿生视觉模型,降低系统输入端的数据冗余;设计了一种多图像平滑加权融...为了解决单相机平台受高分辨率与大视场角之间矛盾制约的问题,本文提出了一种大视场、高分辨率、无色差的复眼相机阵列系统。结合人眼视觉成像理论,建立非均匀采样的仿生视觉模型,降低系统输入端的数据冗余;设计了一种多图像平滑加权融合算法,实现大视场图像无缝拼接;提出了一种基于多级迭代直方图匹配的色彩校正算法,提高了不同子相机间的色彩一致性;利用相邻子相机间重叠区域,对感兴趣区域(Region of Interest,ROI)进行多图像超分辨率重建。最终搭建了曲面相机阵列系统,实现了无色差大视场高分辨率图像的获取。实验结果表明,该系统能够达到单个子相机9倍的视场角与分辨率,并实现了ROI的4倍超分辨率重建。相比于典型的色彩校正算法HM,本文所提方法的PSNR和HSM指标分别提升了4.1%和15.9%,满足了多相机系统在复杂场景下的大视场、高分辨率、无色差的需求。展开更多
文摘To transfer the color data from a device (video camera) dependent color space into a device? independent color space, a multilayer feedforward network with the error backpropagation (BP) learning rule, was regarded as a nonlinear transformer realizing the mapping from the RGB color space to CIELAB color space. A variety of mapping accuracy were obtained with different network structures. BP neural networks can provide a satisfactory mapping accuracy in the field of color space transformation for video cameras.
基金co-supported by the National Natural Science Foundation of China(Nos.12102284,12172242,12332017)the Shanxi Province Science Foundation for Youths,China(No.20210302124262)the Chunhui Project Foundation of the Education Department of China(No.202200257)。
文摘A novel single color camera trichromatic mask 3D-PIV technique suitable for measurement of complex flow fields in confined spaces is presented in this paper.By using a trichromatic mask to modulate the imaging optical path of a color camera,the RGB(Red,Green,and Blue)channels of the photosensitive chip were used to record full-frame full-resolution images of tracer particles from three viewing angles.The MLOS-SMART particle reconstruction algorithm was used to obtain three-dimensional particle distribution matrix from particle trichromatic mask images.The impact of parameters such as the inter-hole spacing and hole diameter of the trichromatic mask on the quality of particle reconstruction was analyzed.Through numerical simulation experiments on artificially synthesized three-dimensional flow fields of Gaussian vortex rings,the practicality of this technique in measuring three-dimensional transient velocity fields and the accuracy of velocity measurements were examined.The accuracy and feasibility of the technique are illustrated based on experimental measurements of a zero-net-mass-flux jet.
基金Supported by National Natural Science Foundation of China(No.60975001 and No.61271412)
文摘An efficient adaptive approximation demosaicking algorithm based on the sampled edge pattern was presented for mosaic images from Bayer color filter array. The proposed algorithm determined edge patterns by four nearest green values surrounding the green interpolation location. Then according to the edge patterns, different adaptive interpolation steps were applied. Simulations on 12 Kodak photos and 15 IMAX high-quality images showed that the proposed method outperformed the other four demosaicking methods (bilinear, effective color interpolation, Lu's method and Chen's method) for average color peak signal to noise ratios and maintained a relatively low complexity owing to constant color-difference interpolation step and a reasonable terminating condition of iteration.
文摘The use of Infrared Thermal Scanners proved to be very useful in lots of applications. Using different color palettes, temperatures can be well-represented in the resulting image. However, most color palettes in hot tropical places like the Philippines are unsuitable since the ambient temperature is almost the same as the scanned object or person. This study evaluates twelve (12) known and used color palettes in the market to determine the most suitable for tropical places using the edge/border tracing algorithms Sobel-Feldman and Laplacian. The result shows that color palettes with the most colors produce more noise, making it difficult to distinguish the object scanned from the background. On the other hand, color palettes with three or fewer contrasting colors produce crisp and more detailed results. This study helps developers and researchers efficiently use color combinations suitable for hot weather for an effective thermal scanning and image representation.
文摘The infrared camera is a curious object for the animals of Changtang.Often covered in camouflage or army green,it looks very"professional".But once I saw the photos they took,I knew the camouflage did not work at all.Most animals could see the cameras without any problem.Some of them showed various degrees of interest in the cameras,while others acted indifferently.To tell the truth,it is not easy to hide something in Changtang.
文摘为了解决单相机平台受高分辨率与大视场角之间矛盾制约的问题,本文提出了一种大视场、高分辨率、无色差的复眼相机阵列系统。结合人眼视觉成像理论,建立非均匀采样的仿生视觉模型,降低系统输入端的数据冗余;设计了一种多图像平滑加权融合算法,实现大视场图像无缝拼接;提出了一种基于多级迭代直方图匹配的色彩校正算法,提高了不同子相机间的色彩一致性;利用相邻子相机间重叠区域,对感兴趣区域(Region of Interest,ROI)进行多图像超分辨率重建。最终搭建了曲面相机阵列系统,实现了无色差大视场高分辨率图像的获取。实验结果表明,该系统能够达到单个子相机9倍的视场角与分辨率,并实现了ROI的4倍超分辨率重建。相比于典型的色彩校正算法HM,本文所提方法的PSNR和HSM指标分别提升了4.1%和15.9%,满足了多相机系统在复杂场景下的大视场、高分辨率、无色差的需求。
