Parameters
| Name | Explanation |
|---|---|
| Handle1 | The image handle of the original image. This is the image without a digital watermark that is used as a key to compare to another image and check if a watermark exists. (24 bit color images only) |
| Handle2 | The image handle of the image that contains the watermark. (24 bit color images only) |
| Level | The level at which to retrieve the watermark. (From -20 to 20 ) |
Return Value
Returns True (nonzero) if successful, otherwise returns False (0).
Explanation
The CheckSecretImage method retrieves the digital
watermark from an image whose watermark has been set with the
SetSecretImage method. It
CANNOT retrieve other types of watermarks.
To check whether an image contains a watermark, set the image
handle of the original image in the Handle1 parameter and set the
image handle of the image suspected to contain the watermark in the
Handle2 parameter. The Level parameter should be set to a value
that is the same as or slighly smaller than the Level at which the
watermark was embedded into the image using the SetSecretImage method. Using a Level
to retrieve the watermark that differs significantly from the Level
at which the watermark was set will result in no watermark being
retrieved. Furthermore, the orginal image and the watermarked image
must be exactly the same size. If either image has been resized, no
watermark can be retrieved.
If successful the resulting raster image handle is set in the
ImageHandle property or
the Layer(LayerNo).ImageHandle
property dpending on the value set in the LayerNo property. The resulting image
has a black background with the digital watermark appearing in
white. (It is a 1-bit image that is the same size as the images set
in Handle1 and Handle2.)
When the Caption, Message, and ButtonName properties are blank, the
progress dialog box will not be displayed. When the progress dialog
box is displayed, the percentage that the processing has completed
will be shown in the dialog box.
To set a watermark in an image, please refer to the SetSecretImage method.