About Arbortext Styler > Document Preview and Publishing > PTC ALD PDF Configuration File (.appcf) > MonochromeImages element (optional)
MonochromeImages element (optional)
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An attribute of MonochromeImages defines how to compress monochrome images in a PDF file.
This option is ignored for linked images when passthrough is enabled. See Images for information.
Attributes of MonochromeImages
Permitted values
The size to which to downsample images
Number (default value 300)
Algorithm for downsampling
When downsampleMode is set to a value other than off, and the DPI of an image is equal to or above the value of downsampleThreshold, the image is downsampled to downSampleDPI.
linked="original" must be set for Images for downsampling settings to have an effect in PDF output.
off (default)
subsample — fastest, uses nearest pixel from original image
The original image type will not be changed with this method.
average — uses average of the group of pixels surrounding the nearest pixel from the original image
bicubic — slowest but best quality, an enhanced bicubic algorithm
Monochrome images are converted to grayscale to achieve the average values required for average or bicubic modes. This may result in a larger PDF file, although downsampling and compression could make it smaller than including the original (subsample method)..
The threshold size of an input image
Number (default value: 450)
type (required)
Compression type
auto — use the most appropriate compression for the type of image
none — do not compress
ccitt3 — CCITT3
ccitt4 (default) — CCITT4
flate — Flate encoding