CoBRA-CYL-QR: Dataset of QR Codes on Cylindrical Surfaces

Dataset summary The CoBRA-CYL-QR dataset includes 5775 images of QR Codes with various number of alignment patterns (1, 6, 13) on cylindrical surfaces with annotated ground truth. They are all generated with the CoBRA dataset synthesis system which is based on 3D rendering technology. File naming pattern There are two folders in the root directory of the dataset: images and markup. Each image in the images folder is named using the following pattern: aa_bb_cccc_ddddd.png, where aa is the number of alignment patterns in QR Code, bb is the index of used model & texture pair, cccc is the index of camera location on the predefined grid of view points, and ddddd is a unique hash of the image in the entire dataset. The corresponding ground truth for each image is stored under the same file name with the appended .json file extension in the markup folder. Annotation format Each JSON ground truth file contains one JSON object that provides information for the single QR Code located in the image: - barcode symbology (key symbology), always equal to QR_CODE;- barcode dimensions in the number of modules (keys dim1 and dim2);- barcode message (key value) in Base64 encoding;- barcode corner points quadrangle (key quad);- barcode grid of modules (key grid);- barcode curvature value (key curvature);- contours of the three Finder Patterns of QR Code (key finder_patterns);- central modules of the three Finder Patterns of QR Code (key finder_patterns_centers);- contours of the Alignment Patterns of QR Code (key alignment_patterns);- central modules of the Alignment Patterns of QR Code (key alignment_patterns_centers); The vertices of the QR Code quadrangle (quad) are indexed starting from the upper left corner of the code spiraling clockwise.The QR Code grid is stored as a list of module corners which is ordered by rows of QR Code starting from the upper left corner of a QR Code and lasting with its lower right one.Finder Patterns and Alignment Patterns of QR Code are stored in ordered lists under the keys finder_patterns, finder_patterns_centers, alignment_patterns, alignment_patterns_centers where each element is itself an ordered list of points of a pattern. Finder Patterns are stored in the following order: upper left, upper right, lower left.Alignment Patterns are ordered like points in the grid: from the upper left pattern down to the lower right one.Their points (of contours and central modules) are indexed starting from the upper left corner of a pattern spiraling clockwise (like in quad).数据集概述 CoBRA-CYL-QR数据集包含5775张圆柱面上的二维码（QR Code）图像，这些图像的对齐图案（alignment pattern）数量分别为1、6、13三种，且所有样本均附带标注的真实标签（ground truth）。本数据集全部基于搭载三维渲染技术的CoBRA数据集合成系统生成。 文件命名规则 数据集根目录下包含两个子文件夹：images（图像文件夹）与markup（标注文件夹）。images文件夹内的每张图像均遵循以下命名格式：aa_bb_cccc_ddddd.png，其中aa代表二维码的对齐图案数量，bb代表所使用的模型与纹理对的索引，cccc代表预定义视点网格中相机位置的索引，ddddd则为该图像在全数据集中的唯一哈希值。每张图像对应的真实标注文件以相同文件名存储于markup文件夹中，仅附加.json扩展名。 标注格式 每个JSON格式的真实标注文件均包含一个JSON对象，用于描述图像内单张二维码的相关信息： - 条码符号类型（key为`symbology`），其值固定为`QR_CODE`； - 以模块数计量的条码尺寸（键为`dim1`与`dim2`）； - Base64编码格式的条码内容（键为`value`）； - 二维码四角点四边形（key为`quad`）； - 二维码模块网格（key为`grid`）； - 条码曲率值（key为`curvature`）； - 二维码三个定位图案（Finder Pattern）的轮廓（key为`finder_patterns`）； - 二维码三个定位图案的中心模块（key为`finder_patterns_centers`）； - 二维码对齐图案的轮廓（key为`alignment_patterns`）； - 二维码对齐图案的中心模块（key为`alignment_patterns_centers`）； 二维码四角点四边形（`quad`）的顶点索引从二维码左上角开始，按顺时针螺旋方向依次排列。二维码模块网格以模块角点列表形式存储，按二维码的行顺序排列，从左上角起始至右下角结束。二维码的定位图案与对齐图案分别以有序列表形式存储于`finder_patterns`、`finder_patterns_centers`、`alignment_patterns`、`alignment_patterns_centers`键下，每个列表元素均为对应图案的点坐标有序列表。定位图案的存储顺序为：左上角、右上角、左下角。对齐图案的排列顺序与网格点一致：从左上角的图案至右下角的图案依次排列。这些图案的轮廓与中心模块的点坐标均从图案左上角开始，按顺时针螺旋方向索引（与`quad`的索引规则一致）。