Notes about the PDFIN filter In this section • Filters • Security handlers • Line Cap Style • Line Join Style • Line dash patterns • CIE-based color spaces • Special color spaces • Overprint control (overprinting) • Antialias • Patterns • Transformations • Masked images • Inline images • PostScript XObjects • Optional Content • Transparency • Text rendering modes • Text knockout • Text-showing • Composite fonts • Bidirectional text (Arabic and Hebrew) in visual order • Viewer preferences • Links • Bookmarks • Thumbnail images • Page labels • Articles • Presentations • Sub-page navigation • Annotations • Actions • Interactive forms • Digital signatures Filters Description The application that generates the PDF file can encode parts of the information to compress it or to convert it to a portable ASCII representation. This information must be decoded using the corresponding decoding filter. Filters • ASCIIHexDecode • ASCII85Decode • LZWDecode • FlateDecode • RunLengthDecode • CCITTFaxDecode • JBIG2Decode • DCTDecode • JPXDecode • Crypt Comments The Crypt filter is not supported. Security handlers Description The PDF standard security handler enables access permissions and passwords to be specified for a document. Passwords • Owner password. Enables full access to the document. • User password. Enables access to the document. Access permissions Access permissions are specified in the form of flags. There are several types of access permissions, for example, permission to modify or print a document. If any permission flag in the PDF input document is set to “do not allow”, and if the correct Owner password is not specified in the PDFIN filter, the document will be rejected. If the correct Owner password is specified in the PDFIN filter, the document will not be rejected, and the StreamServer will have full access permissions. Comments Documents using the standard security handler have a version (0, 1, 2, 3, or 4) and revision (2, 3, or 4) specification. Only documents using version 1 or 2, and revision 2 or 3, are supported. In addition to the standard security handler, applications can also use other types of security handlers. This type of security handlers is not supported. Line Cap Style Description The line cap style specifies the shape used at the ends of open subpaths (and dashes, if any). Comments The output always uses a projecting square cap. This means the stroke continues beyond the endpoint of the path for a distance equal to half the line width and is then squared off. Line Join Style Description The line join style specifies the shape used at the corners of paths that are stroked. Comments The output always uses a miter join. This means the outer edges of the strokes for the two segments are extended until they meet at an angle. Line dash patterns Description Line dash patterns control the pattern of dashes and gaps used to stroke paths. Comments The PDFIN filter can only handle two values for a dash pattern. CIE-based color spaces Description Colors can be specified independently of the characteristics of a particular output device. Types CalGray, CalRGB, Lab, and ICC-Based. Comments The PDFIN filter does not preserve these colors as calibrated. The colors are converted to device colors using a default method. Special color spaces Description Enables patterns, color mapping, separations, high-fidelity, and multitone color. Types Pattern, Indexed, Separation, and DeviceN. Comments Objects filled with patterns are always filled by a solid color. Indexed, Separation, and DeviceN colors are converted to their underlying color space (typically CMYK or RGB). Overprint control (overprinting) Description The color at a given position on the page is a combination of several painting operations in different colors. Comments Not applicable. Antialias Description Used to smoothen the edges of images. Comments Not applicable. Patterns Description • Tiling pattern – patterns replicated at fixed horizontal and vertical intervals fill the painted area. • Shading pattern – a gradient fill of the painted area. Comments Not applicable. The painted area will be filled by a solid color. Transformations Description Translation, rotation, scaling, and skewing of graphics. Comments Images and text can only be scaled and rotated. Some rotations might not be detected due to round off errors in the PDF. Scaled line graphics is output as a scaled box. Other transformations are applied to the corners of the object. This means the output from the PDFIN filter loses the transformation property. For example, a rotated box is converted to a polygon without rotation. Typically, this means that an object that is transformed in the input is not transformed in the output from the PDFIN filter. Masked images Description Enables the existing background to show through the masked areas. Types • Stencil masking • Explicit masking • Color key masking Comments Masked images are converted to regular images. Transparent areas are filled in with white. Inline images Description Images defined directly within the content stream in which they are painted. Comments Sometimes fails. This means some PDF input documents lose image data. PostScript XObjects Description Graphics objects that contains a fragment of PostScript code. Comments These objects are ignored. Note: Adobe discourages the use of PostScript XObjects. Optional Content Description Refers to sections of PDF documents that can be selectively viewed or hidden. Comments Optional parts are not included in the output from the PDFIN filter. Transparency Description Image transparency. Comments Transparency groups are not supported. Objects in a transparency group do not appear in the output from the PDFIN filter. Text rendering modes Description Stroking, filling, and clipping of text. Comments Only mode 0 (fill text) is supported. Text appears with a solid fill color and no outline. No clipping is performed. Text knockout Description If disabled, overlapping glyphs composites with one another. Comments This is a transparency group feature, and is not supported. Text-showing Description Shows/repositions text on the page. Comments The PDFIN filter cannot include embedded fonts in the LXF for later display. If a font is not available on the host, a generic font is be used instead. Workaround Ensure you have all fonts available, and possibly map the font to a Windows font using the font mapping table. Composite fonts Description Glyphs are obtained from a CIDFont object. Comments The PDFIN filter can only handle Unicode glyphs that fit in 16 bits. Bidirectional text (Arabic and Hebrew) in visual order Description Bidirectional text in visual order must be reordered to logical order before it can be processed by the StreamServer. Comments Not applicable. This means the text cannot be reordered. Viewer preferences Description Controls the way the document is presented on screen. Comments Not applicable. Links Description Links to other pages in the document, to other PDF documents, or an URL link. Comments Not applicable. This means all links are lost. Bookmarks Description Hierarchical navigation tree. Comments Not applicable. This means all bookmarks are lost. Thumbnail images Description Representation of the document in a miniature form. The user can click a thumbnail to navigate to the corresponding page. Comments Not applicable. This means all thumbnails are lost. Page labels Description Page labels displayed in, for example, the table of contents. Example The first five pages in the document are numbered in roman numerals, and the remainder of the document is numbered in arabic. Comments Not applicable. This means all page labels are lost. Articles Description Sequences of content that are logically connected but not physically sequential. Comments Not applicable. This means all articles are lost. Presentations Description Slide-shows (automatic or user controlled). Comments Not applicable. This means all presentations are lost. Sub-page navigation Description Navigation between different stages of the same page. For example, switching bullet points on and off. Comments Not applicable. This means all sub-page navigations are lost. Annotations Not applicable. Actions Not applicable. Interactive forms Not applicable. Digital signatures Not applicable.