  In this paper, an effective method was introduced to steganography of text
document in the host image. In the available steganography methods, the message
has a random form. Therefore, the embedding capacity is generally low. In the
proposed method, the main underlying idea was the sparse property of scanned
documents. The scanned documents were converted from gray-level form to binary
values by halftoning idea and then the information-included parts were
extracted using the improved quadtree and separated from document context.
Next, in order to compress the extracted parts, an algorithm was proposed based
on reading the binary string bits, ignoring the zero behind the number, and
converting them to decimal values. Embedding capacity of the proposed method is
higher than that of other available methods with a random-based message.
Therefore, the proposed method can be used in the secure and intangible
transfer of text documents in the host image.
