PDFlib 8 Windows COM/.NET Tutorial

tion) if the user coordinate system hasn’t been scaled (since there are 72 default units to
an inch).
Cookbook A full code sample can be found in the Cookbook topic images/image_dimensions. It shows how
to get the dimensions of an image and how to place it with various sizes.
Color space of imported images. Except for adding or removing ICC profiles and applying
a spot color according to the options provided in load_image( ), PDFlib will generally
try to preserve the native color space of an imported image. However, this is not
possible for certain rare combinations, such as YCbCr in TIFF which will be converted to
RGB.
PDFlib does not perform any conversion between RGB and CMYK. If such a conversion
is required it must be applied to the image data before loading the image in PDFlib.
Multi-page images. PDFlib supports GIF, TIFF and JBIG2 images with more than one
image, also known as multi-page image files. In order to use multi-page images use the
page option in load_image( ):
image = p.load_image("tiff", filename, "page=2");
The page option indicates that a multi-image file is to be used, and specifies the number
of the image to use. The first image is numbered 1. This option may be increased until
load_image( ) returns -1, signalling that no more images are available in the file.
Cookbook A full code sample for converting all images in a multi-image TIFF file to a multi-page PDF file
can be found in the Cookbook topic images/multi_page_tiff.
Inline images. As opposed to reusable images, which are written to the PDF output as
image XObjects, inline images are written directly into the respective content stream
(page, pattern, template, or glyph description). This results in some space savings, but
should only be used for small amounts of image data (up to 4 KB). The primary use of
inline images is for bitmap glyph descriptions in Type 3 fonts; inline images are not recommended
for other situations.
Inline images can be generated with the load_image( ) interface by supplying the
inline option. Inline images cannot be reused, i.e., the corresponding handle must not be
supplied to any call which accepts image handles. For this reason if the inline option has
been provided load_image( ) internally performs the equivalent of the following code:
p.fit_image(image, 0, 0, "");
p.close_image(image);
Inline images are only supported for imagetype=ccitt, jpeg, and raw. For other image
types the inline option will silently be ignored.
OPI support. When loading an image additional information according to OPI (Open
Prepress Interface) version 1.3 or 2.0 can be supplied in the call to load_image( ). PDFlib
accepts all standard OPI 1.3 or 2.0 PostScript comments as options (not the corresponding
PDF keywords!), and will pass through the supplied OPI information to the generated
PDF output without any modification. The following example attaches OPI information
to an image:
180 Chapter 7: Importing Images and PDF Pages (Edition for COM, .NET, and REALbasic)