Magritte Sphere

# Magritte-Sphere sequence by LISA ULB

The test sequence "Magritte Sphere" is provided by Sarah Fachada, Daniele Bonatto, Mehrdad Teratani, Gauthier Lafruit, members of the LISA department, EPB (Ecole Polytechnique de Bruxelles), ULB (Universite Libre de Bruxelles), Belgium.

 # License:

CC BY-NC-SA

 # Terms of Use:

Anykind of publication or report using this sequence should refer to the following references.

[1] Sarah Fachada, Daniele Bonatto, Mehrdad Teratani, Gauthier Lafruit, "Magritte Sphere Test Sequence", 2021.

@misc{fachada_magritte_2021,
    title = {{Magritte} {Sphere} {Test} {Sequence}},
    author = {Fachada, Sarah and Bonatto, Daniele and Teratani, Mehrdad and Lafruit, Gauthier},
    month = feb,
    year = {2021},
    doi = {10.5281/zenodo.5048265}
}

[2] Sarah Fachada, Daniele Bonatto, Mehrdad Teratani, and Gauthier Lafruit, "Light Field Rendering for non-Lambertian Objects," presented at the Electronic Imaging, 2021.

@inproceedings{fachada_light_2021,
    title = {Light {Field} {Rendering} for non-{Lambertian} {Objects}},
    booktitle = {Electronic {Imaging}},
    author = {Fachada, Sarah and Bonatto, Daniele and Teratani, Mehrdad and Lafruit, Gauthier},
    year = {2021}
}

 # Production:

Laboratory of Image Synthesis and Analysis, LISA department, EPB, Universite Libre de Bruxelles, Belgium.

 # Content:

This dataset contains a test scene created and rendered with Blender [1] and the addon script [2] extended for Blender 2.8. We provide the Blender file and the rendered scene.

The scene contains a non-Lambertian (transparent-refractive (T) or mirror-specular (M)) sphere rendered in a regular camera array of 21x21 cameras.

In addition to the 3D model, we provide the rendered images : resolution of 2000x2000, the cameras are parallel, with a principal point at the center of the image.

The dataset contains:
 - a `camera.json` file in OMAF coordinates system (Camera position: X: forwards, Y:left, Z: up, Rotation: yaw, pitch, roll) [3],
 - a `parameters.cfg` generated with [2],
 - a `texture_M` folder containing the rendered views in png format for the mirror object,
 - a `texture_T` folder containing the rendered views in png format for the transparent object,
 - a `mask` folder containing the mask indicating the sphere,
 - a `depth` folder containing the associated depth maps in exr format.

 # References and links:

[1] Blender Online Community, "Blender - a 3D modelling and rendering package." Blender Institute, Amsterdam: Blender Foundation, 2020.

[2] K. Honauer, O. Johannsen, D. Kondermann, and B. Goldluecke, "A Dataset and Evaluation Methodology for Depth Estimation on 4D Light Fields" in Asian Conference on Computer Vision, 2016,
https://github.com/lightfield-analysis/blender-addon
https://github.com/dbonattoj/blender-addon

[3] B. Kroon, "Reference View Synthesizer (RVS) manual [N18068]," ISO/IEC JTC1/SC29/WG11, Macau SAR, China, p. 19, Oct. 2018.
https://mpeg.chiariglione.org/standards/mpeg-i/omnidirectional-media-format

# Magritte-Sphere测试序列 —— ULB-LISA实验室出品

本测试序列“Magritte Sphere”由比利时布鲁塞尔自由大学（ULB, Université Libre de Bruxelles）布鲁塞尔高等理工学院（EPB, Ecole Polytechnique de Bruxelles）LISA实验室的Sarah Fachada、Daniele Bonatto、Mehrdad Teratani与Gauthier Lafruit共同提供。

# 授权协议：
知识共享署名-非商业性使用-相同方式共享（CC BY-NC-SA）

# 使用条款：
凡使用本序列制作出版物或研究报告的，均需引用如下参考文献。

[1] Sarah Fachada, Daniele Bonatto, Mehrdad Teratani, Gauthier Lafruit, "Magritte Sphere Test Sequence", 2021.

@misc{fachada_magritte_2021,
title = {{Magritte} {Sphere} {Test} {Sequence}},
author = {Fachada, Sarah and Bonatto, Daniele and Teratani, Mehrdad and Lafruit, Gauthier},
month = feb,
year = {2021},
doi = {10.5281/zenodo.5048265}
}

[2] Sarah Fachada, Daniele Bonatto, Mehrdad Teratani, and Gauthier Lafruit, "Light Field Rendering for non-Lambertian Objects," presented at the Electronic Imaging, 2021.

@inproceedings{fachada_light_2021,
title = {Light {Field} {Rendering} for non-{Lambertian} {Objects}},
booktitle = {Electronic {Imaging}},
author = {Fachada, Sarah and Bonatto, Daniele and Teratani, Mehrdad and Lafruit, Gauthier},
year = {2021}
}

# 制作机构：
比利时布鲁塞尔自由大学（ULB）布鲁塞尔高等理工学院（EPB）LISA（图像合成与分析）实验室

# 数据集内容：
本数据集包含使用Blender[1]及适配Blender 2.8的扩展插件脚本[2]创建并渲染的测试场景，我们同时提供Blender源文件与渲染完成的场景文件。

该场景包含一个非朗伯体（non-Lambertian）球体，分为透光折射型（T）与镜面反射型（M）两类，使用21×21规格的规则相机阵列完成渲染。

除3D模型外，本数据集还提供渲染图像：分辨率为2000×2000，相机采用平行投影模式，主点位于图像中心位置。

本数据集包含以下文件与文件夹：
- 采用全向媒体格式（OMAF）坐标系的`camera.json`文件（相机坐标定义：X轴为前进方向，Y轴为左侧，Z轴为上方；旋转参数依次为偏航（yaw）、俯仰（pitch）、滚转（roll））[3]，
- 由脚本[2]生成的`parameters.cfg`配置文件，
- `texture_M`文件夹：存储镜面反射型物体的渲染视图，格式为PNG，
- `texture_T`文件夹：存储透光折射型物体的渲染视图，格式为PNG，
- `mask`文件夹：存储用于标注球体区域的掩码图像，
- `depth`文件夹：存储格式为EXR的配套深度图。

# 参考文献与链接：

[1] Blender Online Community, "Blender - a 3D modelling and rendering package." Blender Institute, Amsterdam: Blender Foundation, 2020.

[2] K. Honauer, O. Johannsen, D. Kondermann, and B. Goldluecke, "A Dataset and Evaluation Methodology for Depth Estimation on 4D Light Fields" in Asian Conference on Computer Vision, 2016,
https://github.com/lightfield-analysis/blender-addon
https://github.com/dbonattoj/blender-addon

[3] B. Kroon, "Reference View Synthesizer (RVS) manual [N18068]," ISO/IEC JTC1/SC29/WG11, Macau SAR, China, p. 19, Oct. 2018.
https://mpeg.chiariglione.org/standards/mpeg-i/omnidirectional-media-format