Fujiyoshi Lab's PDF Tools are simple processing tools for PDF files consisting of the following three tools: "PDFcontentEraser", "PDFfontChanger" and "PDFcontentExtracter."
They are developed in Java using Apache PDFBox library.
PDFcontentEraser is a tool to remove a certain type of elements in a PDF file. A PDF file mainly consists of characters, images, paths, and shadings. This tool can selectively erase all elements of a certain type.
PDFfontChanger is a tool to change a selection of fonts in a document. As a default setting, all fonts are replaced by "Universal Design Font for Digital Textbooks" (UD font), developed by Morisawa Inc.
PDFcontentExtracter is a tool to retrieve the components of a PDF file. It is designed as a command line tool. It can extract images, character information (position, bounding box, font name, Unicode, and color) and the shapes of paths. This tool can output in the following three forms: (1) character information, image location and path location in XML, (2) image files in PNG, and (3) the shapes of paths, the shapes of characters and the locations of images in SVG.