How do I separate text layer from the rest of the graphics on the page?


We convert pdf files to another document format. here your product
comes in. Is there a way to merge all graphical elements in a pdf-page
except from the text elements?

meaning that all graphics including the transparent will be merged
into a single "image" or element and then the text elements are lying
above it.

You could separate text from the rest of the graphics on the page
using the approach similar to the one illustrated in ElementEdit
sample project (
samplecode.html#ElemenEdit). In ElementEdi sample all images on the
page are removed and text color is changed to blue. Using the similar
approach you can remove all text from the page (or separate the page
into text and 'everything else'). You can subsequently feed the
temporary pages to PDFDraw class or convert then to the other format.