Legacy Survey sky image for Voronoi segmentation tutorial

Input dataset for the GTN tutorial titled 'Voronoi segmentation'. The dataset contains two images: Grayscale image (L mode): A grayscale version of the original three-channel image, obtained using pillow python package Seed image: generated through the following preprocessing steps: Increasing the dynamic range Smoothing Histogram equalization Thresholding These images are processed versions of the original sky image part of Legacy Survey DR 10 that can be directly downloaded using this link. This image is taken around the region defined by R.A.=53.16216667 deg. and Dec.=-27.79149167 deg. with a pixel scale of 0.262 arcsec. The original image is published under Creative Commons Attribution 4.0 International License licence by Legacy Surveys / D. Lang (Perimeter Institute). Acknowledgments for all Data from the Legacy Surveys. An overview of the Legacy Surveys is available in Dey et al. (2019).本数据集为题为《Voronoi分割（Voronoi segmentation）》的GTN教程所用输入数据集。该数据集包含两张图像： 1. 灰度图像（L模式）：采用Python Pillow库处理得到的原始三通道图像的灰度版本 2. 种子图像（Seed image）：通过以下预处理步骤生成： - 动态范围扩展 - 平滑处理 - 直方图均衡化 - 阈值处理 上述图像均为属于遗留巡天第10次数据发布（Legacy Survey DR 10）的原始天区图像的加工版本，可通过本链接直接下载。该图像拍摄于赤经（R.A.）53.16216667°、赤纬（Dec.）-27.79149167°附近区域，像素比例尺为0.262角秒。 本原始图像由遗留巡天（Legacy Surveys）/ D. Lang（周长研究所（Perimeter Institute））依据知识共享署名4.0国际许可协议（Creative Commons Attribution 4.0 International License）发布。谨向所有提供遗留巡天（Legacy Surveys）数据集的相关方致以谢意。 关于遗留巡天（Legacy Surveys）的综述性内容可参考Dey等人（2019）的研究。