Like a macro, an Image Preset is a predefined collection of sizing and formatting commands saved under a name. To understand how Image Presets work, suppose your web site requires each product image to appear at two different sizes: 500 x 500 pixels and 150 x 150 pixels. You create two Image Presets, one called “Enlarge” to display images at 500x500 pixels and one called “Thumbnail” to display images at 150 x 150 pixels. To deliver images at the “Enlarge” and “Thumbnail” size, a Dynamic Media Image Server looks up the definition of the Enlarge Image Preset and Thumbnail Image Preset. Then the server dynamically generates an image at the size and formatting specifications of each Image Preset.
Dynamic Media Classic comes with several “best practice” Image Presets that are already set up for you to use. Administrators can create new Image Presets as well. To create an Image Preset, you can start from scratch or you can start from an existing one and save it under a new name.
Images that are reduced in size when they are delivered dynamically from a server can lose sharpness and detail. For this reason, each Image Preset contains formatting controls for optimizing an image when it is delivered at a particular size. These controls make sure that your images are sharp and clear when they are delivered to your web site or application.
You can create your own Image Presets if you are a company administrator. You can create new Image Presets or start with a default Image Preset that Dynamic Media Classic provides, edit it, and save it with a new name.
To create an Image Preset
Click Setup > Image Presets.
You can browse to an Image Preset name on this screen to preview an existing Image Preset. When you select an Image Preset name, the sample image in the Preview window changes size and appearance.
Do one of the following:
Editing an Image Preset
Browse to the Image Preset that is most like the one you want to create and then click Edit.
Enter a name for the Image Preset.
Enter Width and Height measurements in pixels. These measurements determine the size at which images are delivered.
Fill in the Add Preset or Edit Preset screen. For details, see Image Preset options.
Dynamic Media Classic recommends these “best practice” option choices to start:
Choose JPEG or another format that meets your requirements. All web browsers support the JPEG image format; it offers a good balance between small files sizes and image quality. However, JPEG format images use a lossy compression scheme that can introduce unwanted image artifacts if the compression setting is too low. For that reason, Dynamic Media Classic recommends setting the compression quality (on the slider) to 75. This setting offers a good balance between image quality and small file size.
Do not select Sharpening (this sharpening filter offers less control than Unsharp Masking settings).
Unsharp Masking (USM) options
Enter the settings shown here:
|Preset type||Size||USM: Amount||USM: Radius||USM: Threshold|
|Cross-Sell (mini-thumbnail)||75 x 75||1.5||0.8||5|
|Thumbnail||150 x 150||1.1||1||5|
|Main||350 x 350||1||1||6|
|Enlarge||500 x 500||1.2||1.2||5|
The Dynamic Media Classic “best practice” options for creating Image Presets listed here are general recommendations; sharpening is highly subjective. These “best practice” settings were based on a 2000 x 2000 master image; settings for larger or smaller masters can be different. If you want to adjust the Unsharp Masking settings, Dynamic Media Classic recommends these ranges:
Between .8 and 1.5.
Between .6 and 2.
To delete an Image Preset, select it on the Image Presets screen and select the Delete button.