How to remove only text from a page

Thanks, I read the developer guide :)
But I did not find the ability to delete text, as well as the ability to copy all content without text..

Dear sir，
Could you please give a sample to draw functionality you can overwrite these areas with white colour above certain text.
High appreciation for your support!

Hi,

If there is no built-in solution nor a better suggestion for this and you REALLY want to have the job done, you can try to eliminate each character in the content stream. 
Usually text looks like this:
(HELLO WORLD) or like this:
(H) 2.342 (E) 2.122 (L) 2.214 (L) 2.434 (O) 9.342 (W) 2.12 (O) 2.21 (R) 2.34 (L) 2.12 (D) 
Now you can try to replace all (H)s and (E)s and so on with one space in brackets "( )" and each full word found by text extraction with spaces without brackets:

Select a ContentStream and call 
DebenuPDFLibrary1811.ReplaceTag("HELLO", "     ")
DebenuPDFLibrary1811.ReplaceTag("WORLD", "     ")
DebenuPDFLibrary1811.ReplaceTag("(H)", "( )")
DebenuPDFLibrary1811.ReplaceTag("(E)", "( )")
and repeat it with the complete alphabet.
Please check if your graphs are affected. No warranty!

Feedback appreciated

Martin

Sopracenery wrote: ...you can try to eliminate each character in the content stream.  Usually text looks like this: (HELLO WORLD) or like this: (H) 2.342 (E) 2.122 (L) 2.214 (L) 2.434 (O) 9.342 (W) 2.12 (O) 2.21 (R) 2.34 (L) 2.12 (D) ...