- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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DeepLens
摘要： We aim to generate high resolution shallow depth-of-field (DoF) images from a single all-in-focus image with controllable focal distance and aperture size. To achieve this, we propose a novel neural network model comprised of a depth prediction module, a lens blur module, and a guided upsampling module. All modules are differentiable and are learned from data. To train our depth prediction module, we collect a dataset of 2462 RGB-D images captured by mobile phones with a dual-lens camera, and use existing segmentation datasets to improve border prediction. We further leverage a synthetic dataset with known depth to supervise the lens blur and guided upsampling modules. The effectiveness of our system and training strategies are verified in the experiments. Our method can generate high-quality shallow DoF images at high resolution, and produces significantly fewer artifacts than the baselines and existing solutions for single image shallow DoF synthesis. Compared with the iPhone portrait mode, which is a state-of-the-art shallow DoF solution based on a dual-lens depth camera, our method generates comparable results, while allowing for greater flexibility to choose focal points and aperture size, and is not limited to one capture setup.
关键词： Neural Network,Shallow Depth of Field
更新于2025-09-23 15:23:52
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Synthetic Bessel light needle for extended depth-of-field microscopy
摘要： An ultra-long light needle is highly desired in optical microscopy for its ability to improve the lateral resolution over a large depth of field (DOF). However, its use in image acquisition usually relies on mechanical raster scanning, which compromises between imaging speed and stability and thereby restricts imaging performance. Here, we propose a synthetic Bessel light needle (SBLN) that can be generated and scanned digitally by complex field modulation using a digital micromirror device. In particular, the SBLN achieves a 45-fold improvement in DOF over its counterpart Gaussian focus. Further, we apply the SBLN to perform motionless two-dimensional and three-dimensional microscopic imaging, achieving both improved resolution and extended DOF. Our work is expected to open up opportunities for potential biomedical applications.
关键词： depth-of-field microscopy,motionless imaging,Bessel light needle,digital micromirror device
更新于2025-09-23 15:21:21
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A Beginners' Guide to Scanning Electron Microscopy || Imaging with the SEM
摘要： The scanning electron microscope is routinely used to characterize wide-ranging materials due to its ease of operation and relatively straightforward sample preparation as well as due to simple image interpretation. New users can readily obtain images after little practice. However, high-resolution microscopy and examination of “difficult” samples require experience and know-how of the principles of image formation in the SEM. This chapter describes the role of various operational parameters used during microscopy in more detail. The effect of these parameters on contrast, resolution, and depth of field depicted by images is discussed. Pros and cons of microscopy conditions that have a direct bearing on the quality of images, type of information obtained, and image interpretation are elaborated. Guidelines for operation and upkeep of the SEM instrument are also summarized in this chapter.
关键词： high-resolution microscopy,operational parameters,resolution,scanning electron microscope,SEM,image formation,contrast,microscopy conditions,image interpretation,depth of field
更新于2025-09-23 15:19:57
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Depth of Field Extension in Laser Speckle Contrast Imaging
摘要： A new technique that can increase the depth of field (DOF) for in vivo tissue imaging is presented. Extended DOF for the imaging of strongly scattering media is realized through combining laser speckle contrast imaging (LSCI) with light field (LF) microscopy. To the best of our knowledge, it is for the first time to combine these two imaging techniques into one system to provide enhanced functionality. The entire imaging process requires only one single detection with no mechanical adjustment involved. The feasibility and capability of the proposed technique is experimentally demonstrated in volumetric flow speed measurement.
关键词： laser speckle contrast imaging,Light field,depth of field
更新于2025-09-16 10:30:52
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[IEEE 2018 International Conference on 3D Vision (3DV) - Verona, Italy (2018.9.5-2018.9.8)] 2018 International Conference on 3D Vision (3DV) - DSR: Direct Self-Rectification for Uncalibrated Dual-Lens Cameras
摘要： With the developments of dual-lens camera modules, depth information representing the third dimension of the captured scenes becomes available for smartphones. It is estimated by stereo matching algorithms, taking as input the two views captured by dual-lens cameras at slightly different viewpoints. Depth-of-field rendering (also be referred to as synthetic defocus or bokeh) is one of the trending depth-based applications. However, to achieve fast depth estimation on smartphones, the stereo pairs need to be rectified in the first place. In this paper, we propose a cost-effective solution to perform stereo rectification for dual-lens cameras called direct self-rectification, short for DSR1. It removes the need of individual offline calibration for every pair of dual-lens cameras. In addition, the proposed solution is robust to the slight movements, e.g., due to collisions, of the dual-lens cameras after fabrication. Different with existing self-rectification approaches, our approach computes the homography in a novel way with zero geometric distortions introduced to the master image. It is achieved by directly minimizing the vertical displacements of corresponding points between the original master image and the transformed slave image. Our method is evaluated on both realistic and synthetic stereo image pairs, and produces superior results compared to the calibrated rectification or other self-rectification approaches.
关键词： depth estimation,stereo rectification,dual-lens cameras,depth-of-field rendering,self-rectification
更新于2025-09-11 14:15:04
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Typical Causes of Errors During Measuring Luminance Distributions in Relation to Glare Calculations
摘要： The number of high luminance light sources commonly used in lighting technology is systematically growing, causing an increase in number of potential problems. One of them is the problem of discomfort glare and ways to measure it. Both calculation and measurement methods connected with this parameter have a series of disadvantages and advantages. Among the serious disadvantages, there can be dominant digital “models” of light sources and luminaires, which do not include, practically, any direct information on luminance distribution. To make the measurement results correspond to the calculation results, computer simulations and visual impression of the people assessing the lighting, the measuring devices should correctly record the analyzed parameters. The accurate parameters recording means the situation under which the measurement result is possibly close to what the human eye records. The there are modern measurement undoubtedly ILMDs - Imaging luminance measuring devices, are potentially ideal to record all parameters used to calculate glare. Research done by the author proves that especially as far as the small light sources are concerned, such as LEDs and multi-source luminaire systems the parameters of the equipment used have a big influence on the measurement results. Especially, an angular field of view of single pixel of the digital sensor, which relates to a CCD or CMOS sensor size, dimensions of single photo-cell, focal length and technology that is used to make this device (B/W, color). A problem of the influence of depth of field of digital recording equipment with respect to the measured luminance values was dealt with. In this paper and presentation, the relationships of ILMD parameters, such as a field of view of a given type of sensor and single photo-element, including the used lens, will be presented.
关键词： sharp depth of field of lens,luminance measurements,glare,ILMD
更新于2025-09-10 09:29:36
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Practical Testing and Evaluation of Plastics || Optical Testing Methods
摘要： Optical testing includes visual inspection with the naked eye and microscopic testing (different microscopy methods). The optical test methods differ in the ability to resolve details and the possible magnifications of the microscopic methods. The term resolution refers to the minimum distance between two objects that can still be observed without the two objects visually merging into each other. Magnification indicates the factor by which the object under investigation appears to be larger than it actually is. Another important concept in microscopy is the depth of field. A low depth of field means that only a specific plane of the sample can be sharply imaged (focused). Areas in front and behind this layer appear blurred. In contrast, an image with a high depth of field provides a good plastic impression of the examined specimen. For example, a large depth of field can be used to observe rough fracture surfaces.
关键词： resolution,microscopy,depth of field,Optical testing,magnification
更新于2025-09-10 09:29:36
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Comprehensive optical design model of the goldfish eye and quantitative simulation of the consequences on the accommodation mechanism
摘要： To further extent our understanding of aquatic vision, we introduce a complete optical model of a goldfish eye, which comprises all important optical parameters for the first time. Especially a spherical gradient index structure for the crystalline lens was included, thus allowing a detailed analysis of image quality, regarding spot size, and wavelength dependent aberration. The simulation results show, that our realistic eye model generates a sufficient image quality, with a spot radius of 4.9 μm which is below the inter cone distance of 5.5 μm. Furthermore, we optically simulate potential mechanical processes of accommodation and compare the results with contradictory findings of previous experimental studies. The quantitative simulation of the accommodation capacity shows that the depth of field is strongly dependent on the resting position and becomes significantly smaller when shorter resting positions are assumed. That means, to enable an extended depth perception with high acuity for the goldfish an adaptive, lens shifting mechanism would be required. In addition, our model allows a clear prediction of the expected axial lens-shift, which is necessary to ensure a sufficient resolution over a large object range.
关键词： Gradient index lens,Accommodation,Depth of field,Goldfish eye model
更新于2025-09-10 09:29:36
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Impact of higher-order aberrations on depth-of-field
摘要： It is well known that depth-of-focus (DOF) is influenced by optical factors (such as pupil size and monochromatic aberrations). However, neural factors such as blur sensitivity and defocus adaptation may play an important role on the extent of DOF. A series of experiments were conducted to study if optical or neural factors are most pertinent in explaining the variability of DOF across subjects. An adaptive optics system with a black and white target, a 3.8-mm artificial pupil, and a subjective criterion (based on objectionable blur) were used to measure depth of field ([DOFi]; DOF computed in the object space) in 11 participants, after at least 6 min of adaptation. This was done under three conditions: (a) with their own higher order aberrations (HOA); (b) after correction of their monochromatic HOA; and (c) after altering the HOA pattern for some participants to reflect the HOA pattern measured for a different participant. Natural DOFi and DOFi after HOA correction were positively correlated (R2 ? 0.461), but a significant decrease in DOFi (21% on average) was found after HOA correction (p ? 0.042). Effect of HOA on the intersubject variability of DOFi was 3.9 times smaller than the effect of the image neural processing. This study shows that DOFi depends on both optical and neural factors, but the latter seems to play a more important role than the former.
关键词： depth of focus,visual optics,wavefront aberrations,depth of field,physiological optics
更新于2025-09-09 09:28:46
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Selective Light Field Refocusing for Camera Arrays Using Bokeh Rendering and Superresolution
摘要： Camera arrays provide spatial and angular information within a single snapshot. With refocusing methods, focal planes can be altered after exposure. In this letter, we propose a light field refocusing method to improve the imaging quality of camera arrays. In our method, the disparity is first estimated. Then, the unfocused region (bokeh) is rendered by using a depth-based anisotropic filter. Finally, the refocused image is produced by a reconstruction-based superresolution approach where the bokeh image is used as a regularization term. Our method can selectively refocus images with focused region being super-resolved and bokeh being esthetically rendered. Our method also enables post-adjustment of depth of field. We conduct experiments on both public and self-developed datasets. Our method achieves superior visual performance with acceptable computational cost as compared to other state-of-the-art methods.
关键词： depth of field (DoF),camera array,superresolution (SR),refocusing,light field (LF),Bokeh
更新于2025-09-09 09:28:46