What is Steganography?
Steganography has its origin in the
Greek words "stegonos" (invisible, hiding) and
"graphos" (graphics, writing style, recording
method). It means a technique for transmitting information
without disclosing it to any other people. Kowa's trademarks,
SteganoSign for Personal and SteganoBank, are derived from
steganography.
Back to Top
SteganoSign for Personal allows users
to select the watermark information. However, the amount
of information that can be embedded depends on the digital
watermark mode.
Back to Top
SteganoSign for Personal allows a
digital watermark to be embedded in the same content more
than once. However, the quality of the content is reduced
each time.
Back to Top
The content containing the embedded
digital watermark is not identical to the original data.
However, it is difficult to recognize this difference just
by looking or listening because the difference seems to
be too subtle for the human eye or ear to detect.
Back to Top
For images, digital watermarks are
retained when files are converted from Bitmap or TIFF to
PICT. Digital watermarks are retained in JPEG files if the
compression rate is low enough to retain the original image
quality.
For music, converting WAVE to another
format such as MP3 causes loss of digital watermark information.
Currently, Kowa is developing digital watermarks that support
MP3 and vector quantization compression methods.
Back to Top
Once embedded, a digital watermark
cannot be removed. The user should back up his or her original
before embedding a digital watermark.
Back to Top
Embedding digital watermarks is the
same as adding "noise," whether the carrier file
contains images or music. SteganoSign for Personal embeds
digital watermarks at such a fine level that they cannot
be recognized by the human eye or ear. Therefore, technically
speaking, there is some loss of quality, but it is difficult
to discern.
Back to Top
Digital watermarks are retained in
images after cropping if enough area is obtained, although
this depends on the digital watermark mode. Gamma correction
and filtering are possible, depending on certain conditions.
If the quality obtained is drastically different from the
original image, the digital watermark is lost.
Back to Top
|
