function WriteHiddenText(const text: AnsiString): Integer;
Description
WriteHiddenText and WriteHiddenData write hidden text or raw data within a true color image. Hidden information is stored inside the image (uses a pixel color modulation) and is independent of the image file format.
Use WriteHiddenText to write a simple string or WriteHiddenData to write a block of bytes (e.g. to embed a hidden image or sound).
Result is the number of bytes written.
Note: The hidden text will be lost if you save the image as Jpeg or if you subsample the colors.