Image Formats and Considerations in FrameMaker
If ePublisher cannot use an original image in the output, or if ePublisher determines it needs to modify the image based on how it is included in the source document, ePublisher rasterizes the image using the options you define for your graphic styles in Style Designer. For example, you can define the dots per inch (DPI) and format for the final images. Rasterization of an image can cause the image to be less clear in the output.
To avoid reduced image quality in your output, and to avoid an extended transformation time during the Image stage and pipeline, review the following considerations:
When ePublisher encounters an anchored frame in your FrameMaker source documents, ePublisher checks for the following conditions:
Is the frame a different size than the original image?
Is there white space in the frame?
Is the image copied into the document, rather than imported by reference?
Is the original image a file format other than .jpg, .gif, .png, or .svg?
Are there additional elements in the frame, such as text boxes, multiple images, or callouts?
If ePublisher determines that any of these conditions apply, ePublisher rasterizes the entire frame and applies the options you defined in Style Designer.
To display images at full size in online output and avoid resizing, which can cause the image to be rasterized, set the By reference graphics use document dimensions option for your graphic styles to Disabled.
If you want ePublisher to rasterize all images according to your Style Designer options, set the By reference graphics option to Disabled for all graphic styles.
When ePublisher finds an image included by-reference that is the original size, is shrink-wrapped, and contains no callouts, ePublisher copies the image directly into the output folder in most cases, bypassing the graphic style options.
To improve the image quality in your output, resize your images as needed using an image editing application before importing them, rather than adjusting the DPI or scale in FrameMaker. Otherwise, an image included by reference retains its original file size, and it is either scaled by the browser or rasterized according to the size of the anchored frame, which can result in a distorted image.
For the best compatibility with most computer monitors, save and import your images at 96 DPI using a format that ePublisher does not rasterize.
Image callouts are useful in many publications. However, text boxes and line drawings cause images to be rasterized, which can make images less clear in your output. Add and edit callouts in your image editing application and then import the single, final image to avoid the rasterization process.
If you use .svg image files, you need to configure the .svg options to specify whether to rasterize these images. Some output formats and some browsers do not support .svg image files.
You can add text boxes with GraphicStyle markers to your images without causing the image to be rasterized, since markers do not affect the appearance or format of an anchored frame.
ePublisher does not include images from FrameMaker Master or Reference pages, and it does not include content outside the main text flow.
Store image files and source documents on the local computer when generating output.
To achieve the best results when inserting images in FrameMaker
Create a unique paragraph format for images. Use the paragraph alignment properties to control the position of your images. Make sure the Fixed check box in the Line Spacing section is not selected for the paragraph format.
Insert an anchored frame in an empty paragraph of the format created in step 1.
Import your image file by reference into the anchored frame rather than copying it into the document. ePublisher supports only .jpg, .gif, .png, and .svg files. ePublisher rasterizes all other formats.
Import the image at the native resolution of the image.
Shrink-wrap the frame (type Esc+m+p with the frame selected) and change its Anchoring Position to At Insertion Point or Below Current Line.