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In general, PDF files can be categorized into two basic types: raster image and searchable text based. Raster image based PDF files are basically images in a PDF wrapper. These types of PDF files offer the advantage of being more difficult to edit than text based PDFs and have the exact same appearance as the original image. On the other hand, searchable text based PDF files offer capabilities such as search and edit, and are typically smaller in size.
When converting from raster images to searchable text based PDF, LEADTOOLS can save a hybrid type of PDF that is a searchable text based PDF but maintains the exact appearance of the original raster image. These types of PDF files are called image over text. In image over text PDFs, the text is formatted as usual, but the portion of the original raster image for each character is overlaid on top of the text. This maintains the look and formatting of the original raster image while still allowing the text content to be searched, selected, copied and pasted.
In addition, they integrate seamlessly with the broad imaging functionality in LEADTOOLS SDKs such as display, color-conversion, image-processing and scanning. If you have a Document Imaging Product, you can also take advantage of annotations and document clean-up.
LEADTOOLS Raster PDF Read Plug-inBelow is a list of features unique to the LEADTOOLS Raster PDF Read Plug-in.
The
LEADTOOLS Raster PDF Read Plug-in is available as an add on
to
Imaging Pro,
Document Imaging
Toolkits,
Medical Imaging
Toolkits and
Vector Imaging Toolkit.
This plug-in also offers decryption capabilities as outlined here and can read the compression types supported by the PDF writer as described here.
Import Capabilities:
- Loads PDF 1.6 files.
- Loads PostScript Language Level 3 files.
- Loads EPS files.
- Support is provided for loading the entire document or a specified set of sequential pages.
- Decryption
- RC4 40-bit key encryption.
- RC4 128-bit key encryption.
- Support for User and Owner passwords.
Controlling page rasterization
- PDF files can be rasterized to 1, 4, 8 and 24 bits per pixel.
- Control the horizontal resolution in dots per inch.
- Control the vertical resolution in dots per inch.
- Use fonts installed by the plug-in or system fonts.
- 2-bit and 4-bit font anti-aliasing.
- 2-bit and 4-bit Graphics anti-aliasing.
LEADTOOLS Raster PDF Write Plug-inBelow is a list of features unique to the LEADTOOLS Raster PDF Write Plug-in.
The
LEADTOOLS Raster PDF Write Plug-in is available as an add on
to
Imaging Pro,
Document Imaging Toolkits,
Medical Imaging Toolkits and
Vector Imaging Toolkit.
Full multi-page write support for PDF is included. You can append, insert, replace or delete a specified page in an existing PDF file.
The plug-in provides a wide range of control options for the resulting image data in terms of compression. These include:
Export Capabilities:
- Save PDF/A.
- PDF with CMYK data support.
- No compression, where the image is embedded inside the file without any compression.
- Compressed using CCITT Group 3, 1 dimension. For 1-bit images.
- Compressed using CCITT Group 3, 2 dimensions. For 1-bit images.
- Compressed using CCITT Group 4. For 1-bit images.
- JPEG compression and YUV 4:4:4 color space loss-less. Bits per pixel: 8 for grayscale, 24 for color.
- JPEG compression and YUV 4:2:2 color space. Bits per pixel: 8 for grayscale, 24 for color.
- JPEG compression and YUV 4:1:1 color space. Bits per pixel: 8 for grayscale, 24 for color.
- JBIG2 compression. Bits per pixel: 1.
- The plug-in also gives you control over the type of
encoding to be used in order to change compressed image
data into a text encoded format. The text encoding
techniques include:
- No text encoding at all.
- Use ASCII 85 text encoding algorithm.
- Use ASCII HEX text encoding technique.
- Encryption
- RC4 40-bit key encryption.
- RC4 128-bit key encryption.
- Support for User password, Owner password permissions.
Advanced PDF Compression (included in the Raster PDF Write Plug-in)
Through Mixed Raster Content (MRC) segmentation, the LEADTOOLS Raster PDF Write Plug-in compressor can automatically break down a page/image into smaller segments, using compression appropriate for that segment. This provides a PDF file with better compression ratios while maintaining high quality than when compared to a standard Raster PDF file.
Advanced PDF Compression includes the following features:
- Supports many compression types:
- ZIP (Flate compression)
- LZW
- FAX CCITT (G3 1D, G3 2D, G4)
- JBIG2
- Lossless JPEG
- JPEG (YUV 4:4:4, YUV 4:2:2 and YUV 4:1:1)
- Produces v1.6 PDF files.
- Provides advanced options to control the process of adding the segments to the PDF file.
- Includes predefined input profiles to specify source
image type. The input profiles supported are:
- Automatic
- Noisy
- Scanned
- Printed
- Computer generated
- Photo
- User: This profile is provided for advanced users.
- Provides control over the compression types that will be used with each type of segment. For example, the user can choose to use JBIG2 compression for 1 bit/pixel segments.
- Background detection is supported. The user can enable background detection which will try to determine the background of the image. In that case, the PDF Compressor will NOT store the background segments, which results in more compact PDF files.