Binary defocusing technique based on complementary decoding with unconstrained dual projectors

Binary defocusing technique can effectively break the limitation of hardware speed, which has been widely used in the real-time three-dimensional (3D) reconstruction. In addition, fusion technique can reduce captured images count for a 3D scene, which helps to improve real-time performance. Unfortunately, it is difficult for binary defocusing technique and fusion technique working simultaneously. To this end, our research established a novel system framework consisting of dual projectors and a camera, where the position and posture of the dual projectors are not strictly required. And, the dual projectors can adjust defocusing level independently. Based on this, this paper proposed a complementary decoding method with unconstrained dual projectors. The core idea is that low-resolution information is employed for high-resolution phase unwrapping. For this purpose, we developed the low-resolution depth extraction strategy based on periodic space-time coding patterns and the method from the low-resolution order to high-resolution order of fringe. Finally, experimental results demonstrated the performance of our proposed method, and the proposed method only requires three images for a 3D scene, as well as has strong robustness, expansibility, and implementation.

Coastal Depth Extraction from Satellites Images

The problems in bathymetry measurement often have gaps or ‘holes’ within the data. As a result, hydrographic surveyors often have sparse data, and even though the data is dense and equal distances, there is still a gap in time. This paper present coastal depth extraction from satellite images. The problem encountered during the bathymetry derivation process and the problem related to the space, distribution and quantity of the Single-beam echo sounder (SBES) data. Therefore, the idea of using spatial interpolation could be a suitable approach in solving the problems. This study intends to produce Satellite-Derived Bathymetry (SDB) from Landsat 8 images at Pantai Tok Jembal, Terengganu, Malaysia. The proposed method by first interpolating the SBES point in the calibration data using spatial predictors, i.e. Inverse Distance Weightage, Thin-Plate Spline, Spline with Tension, Universal Kriging, Natural Neighbor, and Topo to Raster. Second, the raster output created from the interpolation process then converts into the point shapefile. Third, intersect function use to eliminate the point whereby not in the domain. Finally, the newly generated SBES points in calibration data ready to apply at the SDB computation process, generating SDB. In continuation, a comparative analysis conducted between six SDB results generated using each different newly generated calibration data. The result indicates SDB utilizes with Universal Kriging-newly generated calibration data (RMSE: 0.718 m) was the best result. To summarise, this study has successfully attained the research objectives by utilizing the newly generated calibration data in generating SDB. The task of spatial interpolation recreates the SBES data from irregular space and short data to uniform space and long data, which facilitate in pixel to point value extraction and help refine the bathymetry derivation process. Furthermore, the proposed method suitable to be used when the data are not applicable or limited.

The Effect of Sunglint Correction for Estimating Water Depth Using Rationing, Thresholding, and Mean Value Algorithms

Satellite-Derived Bathymetry (SDB) is an alternative for obtaining shallow water depth data. The existence of images with various resolutions, the availability of a complete image band can develop the extraction results. This method is based on the principle of the satellite's visible band to estimate water depth. The mapping of shallow water depth is dependent on water conditions, both its brightness and surface. When the sensor senses a water object, the reflected reflection comes from the surface, and some sensors cannot penetrate the water object. The sun's position and the sensor's point of view when sensing it results in interference from the water surface (Sunglint). The sunglint effect on the image can be reduced by performing RGB band correction with NIR Infrared. This study aims to demonstrate the effect of Sunglint's correction on three SDB approaches, namely Thresholding, Rationing, and Mean Value on Worldview 3 imagery in Karimunjawa Islands, Central Java. This study's results indicate that the Sunglint correction on Worldview 3 imagery affects the depth extraction results. The best results are shown by Sunglint's correction using the Thresholding approach (B2-B7), which produces the best correlation with R2 of 0.7364 and (B7-B2) with R2 = 0.7351. Contrastingly, the lowest correlation was generated using the Mean Value ((B2 + B7) / 2) approach without Sunglint's correction with R2 = 0.4015. So this research proves that the Worldview 3 image with Sunglint correction can provide bathymetry data, especially in shallow waters.

Depth extraction in computational integral imaging based on bilinear interpolation

We proposed a method using a merit function to determine the depth of objects in computational integral imaging by analyzing the existing methods for depth extraction of target objects. To improve the resolution of reconstructed slice images, we use a digital camera moving in horizontal and vertical direction with the set interval to get elemental images with high resolution and bilinear interpolation algorithm to increase the number of pixels in slice image which improves the resolution obviously. To show the feasibility of the proposed method, we carried out our experiment and presented the results. We also compared it with other merit functions. The results show that merit function SMD2 to determine the depth of objects is more accurate and suitable for real-time application.

3D Stereoscopy Video Production: Z-Depth Extraction and Optimized Rendering using Foundry Nuke

This paper proposed an effective and efficient 3D stereo Video production methodology for Stereo conversion of any image or video using the 3D compositing tool Foundry Nuke. For efficient S3D conversion, there are several pipelines uses by video production engineer into the industry. There are several technical issues during the 3D stereo production like spilling, reflection, translucency, occlusion, flickering and noise problems as well due to imperfect calibration. This paper presents a theoretical explanation of the principles of stereo vision systems, followed by a quick review of the state of the art. The research paper concludes with validating the assumption of 3D stereoscopy video conversion with film case studies to execute high-end 3d stereo video production quality with roto-based depth map extraction with optimized render conversion methodology.