Lytro Depth for Standard Plenoptic Cameras - Part 02

The data consists of seven datasets acquired under different zoom and focus settings for a 1st generation Lytro camera. The zoom and focus step settings of each dataset were determined by placing a target object at a pre-determined depth of the encasing of the camera and autofocusing on this object. This allows to define a plane in focus by the main lens that is close the target object. Thus, the focus depth is assumed to be the depth of the target object. The Part 02 contains the datasets captured with a focus depth of 1.5 m. These datasets encompass images for calibration and depth range assessment. Each dataset is provided with a set of calibration plenoptic images since the camera parameters are different for each dataset. The calibration images are different from the depth images to ensure the results do not suffer from any type of overfitting effect. The calibration plenoptic images were captured using a 19×19 calibration grid of 3.18 mm cells placed at different poses and at different depths close to the target object depth bearing in mind that a minimum of 10 poses are required. On the other hand, the depth plenoptic images were captured using two different grid sizes: 19 × 19 grid of 470 6.10 × 6.08 mm cells and 5 × 7 grid of 26.50 × 26.38 mm cells. The grids for the depth plenoptic images were placed parallel to the encasing of the camera and at a regular spacing of 0.05 m from the camera for depth values ranging from 0.05 to 2.00 m. The two grid sizes are used for the depth plenoptic images since the depth range evaluated is wide and it is necessary to have a reasonable number of detections to assess the depth accuracy. The smaller grid size was placed up to a maximum depth of 1.0, 1.5 and 2.0 m according to the focus depth considered 0.05, 0.50 and 1.50 m. The bigger grid size was placed considering all depth range evaluated.本数据集包含7组采集自第一代Lytro相机（1st generation Lytro camera）的数据集，各组数据集的变焦与对焦步长设置均通过以下方式确定：将靶标物体置于相机机壳的预设深度处，并对该物体执行自动对焦。此举可通过主镜头定义一个贴近靶标物体的对焦平面，因此默认对焦深度即为靶标物体所在的深度。其中第02组数据集对应对焦深度为1.5米的采集场景。 这些数据集涵盖了用于校准与深度范围评估的图像。由于每组数据集的相机参数存在差异，因此每组数据集均配套了一套校准光场图像（plenoptic images）。为避免过拟合效应影响评估结果，校准光场图像与深度光场图像采用了不同的采集方案。 校准光场图像的采集使用了规格为19×19、单元尺寸3.18 mm的标定棋盘格，靶标需置于贴近待测深度的不同位姿处，且采集位姿数量不少于10组。 另一方面，深度光场图像则采用两种棋盘格规格采集：其一为19×19规格、单元尺寸6.10×6.08 mm的棋盘格，其二为5×7规格、单元尺寸26.50×26.38 mm的棋盘格。深度光场图像的棋盘格均与相机机壳保持平行，且在深度范围0.05 m至2.00 m内，以0.05 m的固定间距设置于相机前方0.05 m处。选用两种棋盘格规格是因为本次评估覆盖的深度范围较广，需要足够数量的有效检测结果以保障深度精度评估的合理性。其中，小尺寸棋盘格的最大采集深度分别设置为1.0 m、1.5 m和2.0 m，对应对焦深度分别为0.05 m、0.50 m和1.50 m；大尺寸棋盘格则覆盖全部待测深度范围。