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APPE
APPE
Transparency
Introduction
The PDF imaging model supports transparent objects. Transparent objects are processed in two
steps:
1. Flattening:
Divide an area with transparent objects into sub-areas where objects have a constant colour.
A sub-area with images or smooth shading is transformed into an image.
2. Blending:
Combine the colours of overlapping transparent objects into a new colour.
Flatten resolution
Images are flattened at the image resolution. Smooth shades are flattened into 300 dpi images.
Blend colour space
In APPE, the blending colour space is always ignored and transparency blending calculations are
done directly in the output colour space.
Spot colour blending
APPE uses Appearance Based Blending (ABB) when a spot colour is involved in transparency.
ABB is always done in the CIE XYZ colour space.
If spot colour matching is enabled and the spot colour is in the spot colour library: The found
CMYK values are interpreted in the output colour space or in the simulation colour space when a
composite output profile is used.
In other cases the alternative colour associated with the spot colour in the PDF will be used.
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Chapter 6 - PDF
imagePRESS C7010VPS series v2.2
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