Image is skewed
Determines whether the PDF file contains an image that has a
skew transformation applied. Ripping a skewed image from a
PostScript format into a raster (or bitmap format) can be very
time- and memory-intensive.
Image is flipped horizontally
Determines whether the PDF file contains an image that has
been transformed into a mirror image.
Image is not scaled proportionally
Determines whether the PDF file contains an image in which the
X scaling differs from the Y scaling.
To specify how much the X scaling can differ from the Y scaling,
select the
Option
check box and type a number in the adjacent
box. For example, if you select the
Option
check box and type
0.5%, PDF Preflight only detects images in which the X scaling
differs from the Y scaling by more than 0.5%.
Compression
Color or grayscale images
Determines whether the PDF file contains images that are
compressed using one or more of the on-screen options. From
the
Options
menu, select one of the following options:
●
JPEG compressed
. JPEG compression removes image data
and may reduce image quality. It can achieve much smaller
file sizes than ZIP compression.
●
JPEG2000 compressed
. JPEG2000 compression may
remove image data and may reduce image quality. It can
achieve much smaller file sizes than ZIP compression.
Note: If an image is compressed with JPEG2000 compression and
you modify it in Prinergy (for example, downsampling or color
matching the image), Prinergy will not be able to encode it back to
JPEG2000 compression. Therefore, it is recommended to select this
check box, so that these images are detected, and then select the
Fix
check box and select
ZIP
(preferred) or
JPEG
as an alternative
compression type.
●
ZIP compressed
. ZIP compression works well with large
areas of single colors or repeating patterns, such as
screenshots and simple images.
●
LZW compressed
. LZW compression is used in GIF and TIFF
files. It is also suitable for compressing text files.
●
Run Length compressed
. Run Length compression does not
remove data to reduce the file size, so it doesn't affect the
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Chapter 10—Refining
