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461
Adobe Photoshop Help
Saving and Exporting Images
Using Help
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Contents
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461
•
256 pixels by 256 pixels if you expect the image to be cropped, rotated, compressed, or
otherwise modified after watermarking.
•
750 pixels by 750 pixels if you expect the image to appear ultimately in printed form at
300 dpi or greater.
There is no upper limit on pixel dimensions for watermarking.
File compression
In general, a Digimarc watermark will survive lossy compression
methods such as JPEG, though it is advisable to favor image quality over file size (a JPEG
compression setting of 4 or higher works best). In addition, the higher the Watermark
Durability setting you choose when embedding the watermark (see
“Using the Watermark
Durability setting” on page 462
), the better the chances that the watermark will survive
compression.
Workflow
Watermarking should be one of the very last tasks you perform, except for file
compression. Use the following recommended workflow:
•
Make all necessary modifications to your image until it has the desired final appearance
(this includes resizing and color correction).
•
Embed the watermark.
•
If needed, compress the image by saving it in JPEG or GIF format.
•
If the image is intended for printed output, perform the color separation.
•
Read the watermark and use the signal strength meter to verify that the image contains
a watermark of sufficient strength for your purposes.
•
Publish the watermarked image.
Embedding digital watermarks
To embed a watermark, you must first register with Digimarc Corporation—which
maintains a database of artists, designers, and photographers and their contact infor-
mation—to get a unique creator ID. You can then embed the creator ID in your images,
along with information such as the copyright year or a restricted-use identifier.
To embed a watermark:
1
Open the image that you want to watermark. You can embed only one watermark per
image. The Embed Watermark filter won’t work on an image that has been previously
marked.
If you’re working with a layered image, you should flatten the image before marking it;
otherwise, the watermark will affect the active layer only.
Note:
You can add a watermark to an indexed-color image by first converting the image to
RGB mode, embedding the watermark, and then converting the image back to indexed-
color mode. However, the results may be inconsistent. To make sure that the watermark
was embedded, run the Read Watermark filter.
2
Choose Filter > Digimarc > Embed Watermark.
