ViTexOCR; a script to extract text overlays from digital video

The ViTexOCR script presents a new method for extracting navigation data from videos with text overlays using optical character recognition (OCR) software. Over the past few decades, it was common for videos recorded during surveys to be overlaid with real-time geographic positioning satellite chyrons including latitude, longitude, date and time, as well as other ancillary data (such as speed, heading, or user input identifying fields). Embedding these data into videos provides them with utility and accuracy, but using the location data for other purposes, such as analysis in a geographic information system, is not possible when only available on the video display. Extracting the text data from imagery using software allows these videos to be located and analyzed in a geospatial context.

The script allows a user to select a video, specify the text data types (e.g. latitude, longitude, date, time, or other), text color, and the pixel locations of overlay text data on a sample video frame. The script’s output is a data file containing the retrieved geospatial and temporal data. All functionality is bundled in a Python script that incorporates a graphical user interface and several other software dependencies.

ViTexOCR脚本提出了一种基于光学字符识别（Optical Character Recognition, OCR）技术，从带有文字叠加层的视频中提取导航数据的全新方法。过去数十年来，外业勘测录制的视频通常会叠加实时地理定位卫星字幕条，其中包含纬度、经度、日期、时间等信息，以及速度、航向或用户输入识别字段等其他辅助数据。将此类数据嵌入视频可提升其实用性与准确性，但倘若这些位置数据仅显示在视频画面中，则无法将其用于地理信息系统（Geographic Information System, GIS）分析等其他场景。通过软件从图像中提取文本数据，即可让这些视频在地理空间语境下实现定位与分析。该脚本支持用户选择目标视频，指定所需提取的文本数据类型（如纬度、经度、日期、时间等）、文本颜色，以及示例视频帧中叠加文本数据的像素坐标位置。脚本的输出结果为包含提取得到的地理空间与时间数据的数据文件。所有功能均集成在一个Python脚本中，该脚本自带图形用户界面，并依赖若干其他软件组件。