MonochromeImages element (optional)

MonochromeImages	Parent Elements	Required	Child Elements
	Compression	No

This option is ignored for linked images when passthrough is enabled. See Images for information.

Attributes of MonochromeImages

Property

Permitted values

downsampleDPI

The size to which to downsample images

Number (default value 300)

downsampleMode

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)..

downSampleThreshold

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