The basic idea there is you.

What is text layer in pdf. Once they are placed on that artboard they are considered a part of that artboard. PDFill PDF Editor can allow the added PDFill objects visible or invisible in the PDF Document. By default PDFJS does not enable text selection in rendered PDFs.

This been said if you really only used iText to do such kind of. The thing is two figures were placed in a same place in the PDF. The concept of PDF Layers came with the introduction of PDF.

So when you bring your drawings in that you are tracing over you can either paste them in when copied from another program or just use File Place to choose the scans of your drawings on your machine. Im building a view layer to replace the viewer the PDFjs team built. With SpirePDF we can add several kinds of layers such as line image string ellipse rectangle and pie to any page of a new or an existing pdf document.

For the purpose of answering your question text can be visible or invisible. Such PDF files are almost indistinguishable from the original documents and are fully searchable. One is a Figure layer and another one is Default layer it was assigned both figures and contents of the page.

Developers can use PDF layer to set some content to be visible and others to be invisible in the same PDF file. When you convert a Word document to a PDF the content written by the original author forms the content layer. Please support me on Patreon.

Annotations are distinct from the main page content in the PDF file. A text layer is added to the image layer usually placed underneath. Text in searchable PDF documents can be selected copied and marked up.