Images of copper wires with various diameters for validating root image analysis

This image set of copper wires was used for ground truth measurements to validate RhizoVision Explorer, and open-source software for image analysis of plant roots, as described further below. <strong>Preprint of the manuscript:</strong> Seethepalli, A., Dhakal, K., Griffiths, M., Guo, H., Freschet, G. T., York, L. M. (2021). RhizoVision Explorer: Open-source software for root image analysis and measurement standardization. bioRxiv: 2021.2004.2011.439359. doi: https://doi.org/10.1101/2021.04.11.439359 <strong>Methods:</strong> Copper wire samples with average lengths of 30.48 cm and various diameter wire gauges (American Wire Gauge 40, 32, 28, 22, 16, and 10; with the diameter ranging from 0.09–2.59 mm) were used for the validation. For each gauge, two wires were used for a total of 12 wires. The diameter of each wire was measured with a digital micrometer and the length was measured by fitting string to the length of the wire, then measured with a ruler. The surface area and volume for each wire were calculated assuming the wires were cylinders. The average diameter for scans containing multiple wires was calculated as the weighted diameter based on the length of each wire in the scan. The wires were then scanned on an Epson Expression 12000XL flatbed scanner with a transparency unit (overhead light), as common practice for root imaging. The images were digitized at 600 dpi as 16-bit grayscale images and then saved as TIFF (tagged image file format). Scans were taken in 28 combinations from individual wires to all as shown in order to achieve variation in total length, average diameter, total surface area, and total volume. The ZIP file contains these 28 images, as well as a CSV file containing the ground truth data measured or calculated as described above.本铜线图像集用于基准真值（ground truth）测量，以验证用于植物根系图像分析的开源软件RhizoVision Explorer（RhizoVision Explorer），详细说明如下。**稿件预印本：** Seethepalli, A., Dhakal, K., Griffiths, M., Guo, H., Freschet, G. T., York, L. M. (2021). RhizoVision Explorer: Open-source software for root image analysis and measurement standardization. bioRxiv: 2021.2004.2011.439359. doi: https://doi.org/10.1101/2021.04.11.439359 **实验方法：** 本次验证采用平均长度为30.48cm、不同线径规格的铜线样本，线规涵盖美国线规（American Wire Gauge）40、32、28、22、16及10号，对应直径范围为0.09~2.59mm。每种线规选取2根铜线，总计12根样本。采用数字千分尺测量单根铜线的直径，通过将细绳贴合铜线全长后用直尺测量的方式获取其长度。假设铜线为圆柱体，计算其表面积与体积。对于包含多根铜线的扫描图像，其平均直径以单根铜线在扫描图中的长度为权重进行加权计算。参照植物根系成像的常规操作流程，使用搭载透射扫描单元（顶置光源）的爱普生（Epson）Expression 12000XL平板扫描仪对铜线进行扫描。图像以600dpi分辨率数字化为16位灰度图像，并存储为TIFF（标签图像文件格式，Tagged Image File Format）文件。为覆盖总长度、平均直径、总表面积及总体积的变量分布，扫描组合涵盖了从单根铜线到全部12根铜线的28种不同搭配。本压缩包包含上述28张扫描图像，以及一个记录了按前述方法测量或计算得到的基准真值（ground truth）数据的CSV文件。