IMAGE ANALYSIS FOR STEM

STEM 图像分析

• 批准号: 6120554
• 负责人: JOSEPH S WALL
• 金额: $ 0.48万
• 依托单位: BROOKHAVEN SCIENCE ASSOC-BROOKHAVEN LAB
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120554
• 关键词: biomedical resource; informatics; technology /technique

STEM mass measurements have been a mainstay of our program. Several years ago A. Steven developed a set of programs to compute radial density profiles from the projected mass profile measured directly in the STEM. This has been used in many projects involving cylindrical or spherical symmetry-An automatic program ("AutoMass") was developed for particle location, classification, alignment, and mass analysis with spherical or cylindrical density analysis, where appropriate, and is used extensively for analyzing STEM data. Several factors motivated this effort. Particle selection can be by mathematical rather than subjective criteria. Coarse sampling in STEM images creates problems with some programs, degrading the resolution, but can be handled easily in a custom program. Using two or more channels of data recorded multancously from the same pixel may create bookkeeping problems (e.g., large angle minus . small angle signals with appropriate thickness corrections to give hydrogen mapping). Various small nonlinearities in STEM signals can be corrected before or during processing. We have adapted these programs to run on a standard personal computer (PCMass). This cost and makes analysis available to many of our users who do not have image processing facilities. A second Pc program imports 3-D x-ray structures from the Protein Data Bank, projects these in various directions and compares these pixel by pixel with a STEM image, while viewing the differ~nce image and computing'the RMS difference. Small-angle scattering curves can be computed for comparison to neutron or x-ray data. STEM images for the past year are archived on our server and available over Internet or on optical disk. The PCMass program also provides a convenient viewer for these remote files and is provided along with image data.

STEM 质量测量一直是我们计划的支柱。 几年前，A. Steven 开发了一套程序来计算 来自测量的投影质量分布的径向密度分布 直接在 STEM 中。 这已在许多涉及的项目中使用 圆柱或球对称 - 自动程序（“AutoMass”） 被开发用于粒子定位、分类、对齐和 质量分析与球形或圆柱形密度分析，其中 适当，并广泛用于分析 STEM 数据。 一些 因素促使了这一努力。 颗粒选择可以通过 数学标准而不是主观标准。 STEM 中的粗采样 图像会给某些程序带来问题，降低分辨率， 但可以在自定义程序中轻松处理。 使用两个或多个 从同一像素同时记录的数据通道可能会产生 簿记问题（例如，大角度减去小角度信号 并进行适当的厚度校正以给出氢图）。 STEM 信号中的各种小非线性可以在之前进行校正 或在加工过程中。 我们已经调整了这些程序以在 标准个人计算机（PCMass）。 本成本及做出分析 可供许多没有图像处理能力的用户使用 设施。 第二个 PC 程序从 3D X 射线结构导入 蛋白质数据库，将其投影到各个方向并进行比较 这些像素与 STEM 图像，同时查看差异 图像并计算 RMS 差值。 小角散射曲线 可以计算以与中子或 X 射线数据进行比较。 STEM 图像 过去一年的数据都存档在我们的服务器上，并且可以通过 互联网或光盘上。 PCMass 计划还提供 这些远程文件的便捷查看器，并随 图像数据。