Image Processing Documentation Release 1.6

Total Page:16

File Type:pdf, Size:1020Kb

Image Processing Documentation Release 1.6 image_processing Documentation Release 1.6 Mel Mason Jan 16, 2020 Contents: 1 Introduction 1 1.1 Use cases.................................................1 1.2 Installation................................................1 1.3 Quick start................................................2 2 Digital Preservation 3 2.1 Embedded metadata...........................................3 3 JPEG2000 Profile 5 3.1 Kakadu compression parameters.....................................5 3.2 References................................................6 4 JP2 colour profiles for digital preservation7 4.1 Preservation guidelines..........................................7 4.2 JP2 conversion details..........................................7 4.3 Recommendations............................................8 4.4 Testing..................................................9 4.5 Further Reading.............................................9 5 API Reference 11 5.1 DerivativeFilesGenerator......................................... 12 5.2 Validation................................................. 14 5.3 Conversion................................................ 16 5.4 Exceptions................................................ 16 5.5 Kakadu.................................................. 16 6 Indices and tables 19 Python Module Index 21 Index 23 i ii CHAPTER 1 Introduction Image-processing is a Python library that converts a source image (TIFF or JPEG) to a JP2 file with a focus on digital preservation and making sure the conversion is reversible. At the Bodleian we use it to generate the derivative image files we ingest into Digital Bodleian for both delivery and long-term preservation. 1.1 Use cases • An all-in-one workflow to go from source file to derivatives including all validation checks. The defaults are tailored to Digital Bodleian preferences, but this is customisable. • Individual functions to be called separately from a workflow manager like Goobi. • Easy TIFF to JP2 conversion from Python: basic Python wrapper around Kakadu, along with some tested parameter recipes. 1.2 Installation pip install git+https://github.com/bodleian/image-processing.git • Compatible with both Python 2.7 and 3.5+ 1.2.1 Dependencies • Exiftool – yum install perl-Image-ExifTool 1 image_processing Documentation, Release 1.6 – apt install exiftool • Kakadu – If you want to process compressed TIFFs, compile it with libtiff support. In the makefile apps/ make/Makefile-<OS>, add -DKDU_INCLUDE_TIFF to CFLAGS and -ltiff to LIBS • Pillow prerequisites before pip install – May need some image packages installed before pip installation (may not need lcms2 depending on which TIFF formats you’ll be processing) – yum install lcms2 lcms2-devel libtiff libtiff-devel libjpeg libjpeg-devel – The virtual environment’s python binary needs to match the Python.h used by GCC. If necessary, use export C_INCLUDE_PATH=/usr/local/include/python2.7/ • Jpylyzer prerequisites before pip install – Needs a relatively recent pip version to install - it fails on 1.4. 1.3 Quick start To run a full conversion on a TIFF file, with validation, format checks, XMP extraction and creation of a thumbnail JPEG: From the command line: convert_tiff_to_jp2 input.tif In Python: from image_processing.derivative_files_generator import DerivativeFilesGenerator derivatives_gen= DerivativeFilesGenerator(kakadu_base_path="/opt/kakadu") derivatives_gen.generate_derivatives_from_tiff("input.tif","output/folder") To access the validation and conversion functions separately so they can be integrated into a workflow system like Goobi: from image_processing.derivative_files_generator import DerivativeFilesGenerator from image_processing import kakadu, validation derivatives_gen= DerivativeFilesGenerator(kakadu_base_path="/opt/kakadu", kakadu_compress_options=kakadu.DEFAULT_ ,!LOSSLESS_COMPRESS_OPTIONS) # each of these statements can be run separately, with different instances of ,!DerivativeFilesGenerator validation.check_image_suitable_for_jp2_conversion("input.tif") derivatives_gen.generate_jp2_from_tiff("input.tif","output.jp2") derivatives_gen.validate_jp2_conversion("input.tif","output.jp2", check_ ,!lossless=True) To just use Kakadu directly through the wrapper: from image_processing import kakadu kdu= kakadu.Kakadu(kakadu_base_path="/opt/kakadu") kdu.kdu_compress("input.tif","output.jp2", kakadu_options=kakadu.DEFAULT_LOSSLESS_ ,!COMPRESS_OPTIONS) 2 Chapter 1. Introduction CHAPTER 2 Digital Preservation This package has a strong emphasis on digital preservation, as we want to use lossless JP2s as our preservation master files. It was developed with input from our digital preservation team. By default it checks: • the JP2 is valid (using jpylyzer) • the JP2 can be converted back into a TIFF, which – has the same pixels as the source TIFF (or the TIFF we converted from the source JPEG) – has the same colour profile and mode as the source image It does not check: • the technical metadata is correctly copied over to the JP2 (we extract this to a separate file) • the JP2 displays as expected in viewers • JPEG to TIFF conversion, if the source file was a JPEG (beyond checking the colour profiles match). This is a lossy conversion, so the pixels will not be identical We have run tests on a wide sample of source images from our repository. We cannot share this test repository on GitHub due to copyright issues, but if you want to run your own tests these automatic lossless checks should simplify that. The full lossless checks can be disabled in production, but we would recommend keeping them enabled if digital preservation is a concern. Note: our testing has been focused on the source images we ingest, not all possible formats. The check_image_suitable_for_jp2_conversion() function is run when generating derivatives, and should fail for image formats we have not tested. See JP2 colour profiles for digital preservation for some more background information and recommendations. 2.1 Embedded metadata We extract image metadata from the source file to a separate XML file for digital preservation, using Exiftool. Exiftool is a command line tool for reading, writing and editing embedded metadata with very thorough support for image 3 image_processing Documentation, Release 1.6 embedded metadata formats. This separate XML file is stored along with the JP2 in the archive. The metadata in the file is stored in the image metadata format XMP, mapped from whatever formats (EXIF, IPTC etc.) were used in the TIFF file. Exiftool also offers a proprietary XML format which preserves the original format of the metadata fields, but we chose XMP as a widely recognised format for sidecar files, rather than going with a proprietary format that may change in future. 2.1.1 Copying over metadata While the extracted metadata is what we rely on for preservation, we also want to have as much of the original metadata as possible in the JP2 image. Maintaining embedded metadata while converting between image file formats is difficult. All of the image conversion software we’ve tried had problems with embedded metadata. • ImageMagick sometimes produces badly formed metadata in the converted file • Pillow by default doesn’t copy over any metadata. Embedded metadata related functionality is limited • Kakadu only copies over some metadata Because of this, we don’t rely on the image conversion library we use (Pillow) to copy over metadata. Instead, we use Exiftool to copy over metadata after the image is converted, both when converting from JPEG to TIFF and when converting from TIFF to JP2. When copying over to JP2 we map all embedded metadata formats to XMP, as JP2 doesn’t have an official standard for storing EXIF. 4 Chapter 2. Digital Preservation CHAPTER 3 JPEG2000 Profile 3.1 Kakadu compression parameters Digital Bodleian uses a specific set of kdu_compress options (DEFAULT_LOSSLESS_COMPRESS_OPTIONS) for lossless JP2 conversion, and alters the rate and Creversible parameters for lossy JP2 conversion. The terminal commands are as follows: 3.1.1 Lossless kdu_compress -i input.tif -o output.jp2 Clevels=6 Clayers=6 “Cprecincts={256,256},{256,256},{128,128}” “Stiles={512,512}” Corder=RPCL ORGgen_plt=yes ORGtparts=R “Cblk={64,64}” Cuse_sop=yes Cuse_eph=yes - flush_period 1024 Creversible=yes -rate - 3.1.2 Lossy kdu_compress -i input.tif -o output.jp2 Clevels=6 Clayers=6 “Cprecincts={256,256},{256,256},{128,128}” “Stiles={512,512}” Corder=RPCL ORGgen_plt=yes ORGtparts=R “Cblk={64,64}” Cuse_sop=yes Cuse_eph=yes - flush_period 1024 -rate 3 3.1.3 Parameter explanation • Clevels=6 Resolution levels. At least 3 are recommended to help compression. After that, the aim is to have the lowest resolution sub-image be roughly thumbnail-sized, so the optimal value is dependent on image size.1 • Clayers=6 Quality layers. More layers can help with quicker decompression; you can decode only a subset of the layers when dealing with lower resolution images where quality decrease is not noticed.1 1 JPEG 2000 as a Preservation and Access Format for the Wellcome Trust Digital Library 5 image_processing Documentation, Release 1.6 • -rate - Compression rates for each quality layer. An initial value of - is needed to ensure true losslessness, as otherwise some data may be discarded. Subsequent numbers can be added to specify bit-rates for each of the lower quality layers - if they are all left unspecified, as they are here, “an internal heuristic determines a lower bound and logarithmically spaces the layer rates over the range”2 • Creversible=yes Use reversible wavelet and component transforms (required for losslessness)1
Recommended publications
  • PDF/A for Scanned Documents
    Webinar www.pdfa.org PDF/A for Scanned Documents Paper Becomes Digital Mark McKinney, LuraTech, Inc., President Armin Ortmann, LuraTech, CTO Mark McKinney President, LuraTech, Inc. © 2009 PDF/A Competence Center, www.pdfa.org Existing Solutions for Scanned Documents www.pdfa.org Black & White: TIFF G4 Color: Mostly JPEG, but sometimes PNG, BMP and other raster graphics formats Often special version formats like “JPEG in TIFF” Disadvantages: Several formats already for scanned documents Even more formats for born digital documents Loss of information, e.g. with TIFF G4 Bad image quality and huge file size, e.g. with JPEG No standardized metadata spread over all formats Not full text searchable (OCR) inside of files Black/White: Color: - TIFF FAX G4 - TIFF - TIFF LZW Mark McKinney - JPEG President, LuraTech, Inc. - PDF 2 Existing Solutions for Scanned Documents www.pdfa.org Bad image quality vs. file size TIFF/BMP JPEG TIFF G4 23.8 MB 180 kB 60 kB Mark McKinney President, LuraTech, Inc. 3 Alternative Solution: PDF www.pdfa.org PDF is already widely used to: Unify file formats Image à PDF “Office” Documents à PDF Other sources à PDF Create full-text searchable files Apply modern compression technology (e.g. the JPEG2000 file formats family) Harmonize metadata Conclusion: PDF avoids the disadvantages of the legacy formats “So if you are already using PDF as archival Mark McKinney format, why not use PDF/A with its many President, LuraTech, Inc. advantages?” 4 PDF/A www.pdfa.org What is PDF/A? • ISO 19005-1, Document Management • Electronic document file format for long-term preservation Goals of PDF/A: • Maintain static visual representation of documents • Consistent handing of Metadata • Option to maintain structure and semantic meaning of content • Transparency to guarantee access • Limit the number of restrictions Mark McKinney President, LuraTech, Inc.
    [Show full text]
  • Adobe's Extensible Metadata Platform (XMP): Background [DRAFT -- Caroline Arms, 2011-11-30]
    Adobe's Extensible Metadata Platform (XMP): Background [DRAFT -- Caroline Arms, 2011-11-30] Contents • Introduction • Adobe's XMP Toolkits • Links to Adobe Web Pages on XMP Adoption • Appendix A: Mapping of PDF Document Info (basic metadata) to XMP properties • Appendix B: Software applications that can read or write XMP metadata in PDFs • Appendix C: Creating Custom Info Panels for embedding XMP metadata Introduction Adobe's XMP (Extensible Metadata Platform: http://www.adobe.com/products/xmp/) is a mechanism for embedding metadata into content files. For example. an XMP "packet" can be embedded in PDF documents, in HTML and in image files such as TIFF and JPEG2000 as well as Adobe's own PSD format native to Photoshop. In September 2011, XMP was approved as an ISO standard.[ ISO 16684-1: Graphic technology -- Extensible metadata platform (XMP) specification -- Part 1: Data model, serialization and core properties] XMP is an application of the XML-based Resource Description Framework (RDF; http://www.w3.org/TR/2004/REC-rdf-primer-20040210/), which is a generic way to encode metadata from any scheme. RDF is designed for it to be easy to use elements from any namespace. An important application area is in publication workflows, particularly to support submission of pictures and advertisements for inclusion in publications. The use of RDF allows elements from different schemes (e.g., EXIF and IPTC for photographs) to be held in a common framework during processing workflows. There are two ways to get XMP metadata into PDF documents: • manually via a customized File Info panel (or equivalent for products from vendors other than Adobe).
    [Show full text]
  • XMP SPECIFICATION PART 3 STORAGE in FILES Copyright © 2016 Adobe Systems Incorporated
    XMP SPECIFICATION PART 3 STORAGE IN FILES Copyright © 2016 Adobe Systems Incorporated. All rights reserved. Adobe XMP Specification Part 3: Storage in Files NOTICE: All information contained herein is the property of Adobe Systems Incorporated. No part of this publication (whether in hardcopy or electronic form) may be reproduced or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of Adobe Systems Incorporated. Adobe, the Adobe logo, Acrobat, Acrobat Distiller, Flash, FrameMaker, InDesign, Illustrator, Photoshop, PostScript, and the XMP logo are either registered trademarks or trademarks of Adobe Systems Incorporated in the United States and/or other countries. MS-DOS, Windows, and Windows NT are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. Apple, Macintosh, Mac OS and QuickTime are trademarks of Apple Computer, Inc., registered in the United States and other countries. UNIX is a trademark in the United States and other countries, licensed exclusively through X/Open Company, Ltd. All other trademarks are the property of their respective owners. This publication and the information herein is furnished AS IS, is subject to change without notice, and should not be construed as a commitment by Adobe Systems Incorporated. Adobe Systems Incorporated assumes no responsibility or liability for any errors or inaccuracies, makes no warranty of any kind (express, implied, or statutory) with respect to this publication, and expressly disclaims any and all warranties of merchantability, fitness for particular purposes, and noninfringement of third party rights. Contents 1 Embedding XMP metadata in application files .
    [Show full text]
  • Digital Forensics Tool Testing – Image Metadata in the Cloud
    Digital Forensics Tool Testing – Image Metadata in the Cloud Philip Clark Master’s Thesis Master of Science in Information Security 30 ECTS Department of Computer Science and Media Technology Gjøvik University College, 2011 Avdeling for informatikk og medieteknikk Høgskolen i Gjøvik Postboks 191 2802 Gjøvik Department of Computer Science and Media Technology Gjøvik University College Box 191 N-2802 Gjøvik Norway Digital Forensics Tool Testing – Image Metadata in the Cloud Abstract As cloud based services are becoming a common way for users to store and share images on the internet, this adds a new layer to the traditional digital forensics examination, which could cause additional potential errors in the investigation. Courtroom forensics evidence has historically been criticised for lacking a scientific basis. This thesis aims to present an approach for testing to what extent cloud based services alter or remove metadata in the images stored through such services. To exemplify what information which could potentially reveal sensitive information through image metadata, an overview of what information is publically shared will be presented, by looking at a selective section of images published on the internet through image sharing services in the cloud. The main contributions to be made through this thesis will be to provide an overview of what information regular users give away while publishing images through sharing services on the internet, either willingly or unwittingly, as well as provide an overview of how cloud based services handle Exif metadata today, along with how a forensic practitioner can verify to what extent information through a given cloud based service is reliable.
    [Show full text]
  • Preparation Method for TIFF File (*.Tif) Over 300Dpi
    Preparation method for TIFF file (*.tif) over 300dpi Using software with saving function of TIFF file. (e.g. DeltaGraph) 1. Select the figure. 2. On the “File” menu, point to “Export”, and then select “Image”. 3. Click “Option”, and select “Color/Gray-scale”. 4. Select “TIFF” in the “File type” dialog box, and save the file at over “300”dpi. Using Microsoft Excel. A) Using draw type graphics software. (e.g. Illustrator, Canvas, etc.) 1. Select the figure in Excel. 2. Copy the figure and paste into graphics software. 3. On the “File” menu, point to “Save as”, and save the file after select “TIFF (over 300dpi)“ in the “File type” dialog box. Compression “LZW”, “ZIP”, or “JPEG” should be used in compression mode for TIFF file to reduce the file size. B) Simple method Color printing by Excel or PowerPoint graphics 1. Select the figure in Excel or PowerPoint. 2. On the “File” menu, point to “Print”, and select “Microsoft Office Document Image Writer” under “printer”. Click “Properties”, click the “Advanced” tab, and then check “MDI” under “Output format”. 3. Click “OK”、and then close the “Properties”. 4. Click “OK” under “printer” and save the MDI file. 5. Start Windows Explorer. 6. Open the saved MDI file, or right-click of the saved MDI file —in the “Open with” dialog box; click “Microsoft Office Document Imaging”. 7. On the “Tool” menu, point to “Option”. In the “Compression” tab, check “LZW”, and then click “OK”. 8. On the “File” menu, point to “Save as”, and then select “TIFF ” in the “File type” dialog box.
    [Show full text]
  • Understanding Image Formats and When to Use Them
    Understanding Image Formats And When to Use Them Are you familiar with the extensions after your images? There are so many image formats that it’s so easy to get confused! File extensions like .jpeg, .bmp, .gif, and more can be seen after an image’s file name. Most of us disregard it, thinking there is no significance regarding these image formats. These are all different and not cross‐ compatible. These image formats have their own pros and cons. They were created for specific, yet different purposes. What’s the difference, and when is each format appropriate to use? Every graphic you see online is an image file. Most everything you see printed on paper, plastic or a t‐shirt came from an image file. These files come in a variety of formats, and each is optimized for a specific use. Using the right type for the right job means your design will come out picture perfect and just how you intended. The wrong format could mean a bad print or a poor web image, a giant download or a missing graphic in an email Most image files fit into one of two general categories—raster files and vector files—and each category has its own specific uses. This breakdown isn’t perfect. For example, certain formats can actually contain elements of both types. But this is a good place to start when thinking about which format to use for your projects. Raster Images Raster images are made up of a set grid of dots called pixels where each pixel is assigned a color.
    [Show full text]
  • Development of National Digital Evidence Metadata
    JOIN (Jurnal Online Informatika) Volume 4 No. 1 | Juni 2019 : 24-27 DOI: 10.15575/join.v4i1.292 Development of National Digital Evidence Metadata Bambang Sugiantoro Magister of Informatics, UIN Sunan Kalijaga, Yogyakarta, Indonesia [email protected] Abstract- The industrial era 4.0 has caused tremendous disruption in many sectors of life. The rapid development of information and communication technology has made the global industrial world undergo a revolution. The act of cyber-crime in Indonesia that utilizes computer equipment, mobile phones are increasingly increasing. The information in a file whose contents are explained about files is called metadata. The evidence items for cyber cases are divided into two types, namely physical evidence, and digital evidence. Physical evidence and digital evidence have different characteristics, the concept will very likely cause problems when applied to digital evidence. The management of national digital evidence that is associated with continued metadata is mostly carried out by researchers. Considering the importance of national digital evidence management solutions in the cyber-crime investigation process the research focused on identifying and modeling correlations with the digital image metadata security approach. Correlation analysis reads metadata characteristics, namely document files, sounds and digital evidence correlation analysis using standard file maker parameters, size, file type and time combined with digital image metadata. nationally designed the highest level of security is needed. Security-enhancing solutions can be encrypted against digital image metadata (EXIF). Read EXIF Metadata in the original digital image based on the EXIF 2.3 Standard ID Tag, then encrypt and insert it into the last line.
    [Show full text]
  • JPEG Standard
    JPEG standard JPEG: “Joint Photographic Experts Group” Formally: ISO/IEC JTC1/SC29/WG10 Working Group 10 International (JBIG, JPEG) Organization for Subcommittee 29 Standardization Joint ISO/IEC (Coding of Audio, Technical International Picture, Multimedia Committee Electrotechnical and Hypermedia (Information Commission Information) Technology) Joint effort with CCITT (International Telephone and Telegraph Consultative Committee, now ITU-T) Study Group VIII Work commenced in 1986 International standard ISO/IEC 10918-1 and CCITT Rec. T.81 in 1992 Widely used for image exchange, WWW, and digital photography Motion-JPEG is de facto standard for digital video editing Bernd Girod: EE398A Image and Video Compression JPEG standard no. 1 JPEG: image partition into 8x8 block 8x8 blocks Padding of right boundary blocks Padding of lower boundary blocks Bernd Girod: EE398A Image and Video Compression JPEG standard no. 2 Baseline JPEG coder DC Huffman tables dc quantization indices Differential coding VLC Level 8x8 Uniform Compressed scalar image data input offset DCT quantization image Zig-zag Run-level scan coding VLC Compressed image data ac quantization indices Quantization tables AC Huffman tables Bernd Girod: EE398A Image and Video Compression JPEG standard no. 3 Recommended quantization tables Based on psychovisual threshold experiments Luminance Chrominance, subsampled 2:1 16 11 10 16 24 40 51 61 17 18 24 47 99 99 99 99 12 12 14 19 26 58 60 55 18 21 26 66 99 99 99 99 14 13 16 24 40 57 69 56 24 26 56 99 99 99 99 99 14 17 22 29 51 87 80 62 47 66 99 99 99 99 99 99 18 22 37 56 68 109 103 77 99 99 99 99 99 99 99 99 24 36 55 64 81 104 113 92 99 99 99 99 99 99 99 99 49 64 78 87 103 121 120 101 99 99 99 99 99 99 99 99 72 92 95 98 112 100 103 99 99 99 99 99 99 99 99 99 [JPEG Standard, Annex K] Bernd Girod: EE398A Image and Video Compression JPEG standard no.
    [Show full text]
  • EXIF: a Format Is Worth a Thousand Words
    NATIONAL LAW ENFORCEMENT AND CORRECTIONS TECHNOLOGY CENTER A program of the Office of Justice Programs’ National Institute of Justice From Winter 2007 TechBeat TECH b • e • a • t Dedicated to Reporting Developments in Technology for Law Enforcement, Corrections, and Forensic Sciences EXIF: A Format Is Worth A Thousand Words he National Center for Missing & Exploited Children if they are used only to open the file. If, however, these T revealed in a June 2005 study that 40 percent of arrest- programs are used to modify an image, they can destroy ed child pornography possessors had both sexually the Exif data. victimized children and were in possession of child pornog- The most important data may be the thumbnail image raphy. Due in part to the increasing prevalence of child exploitation and pornography, the digital photograph has linked to the photograph. Thumbnails are saved in their now become a fixture in gathering and examining forensic own hidden file (a thumbs.db file placed in folders con- evidence in such cases. taining images on the computer), and changes to an image may not always transfer to the corresponding Investigators who frequently handle child pornogra- thumbnail. If an original image is wiped from a disk using phy cases usually have (or know where to access) the a program such as Secure Clean™ or BCWipe®, the thumb- tools and the knowledge to obtain evidence associated nail may still be available. Officers have encountered situ- with contraband images. Nevertheless, law enforcement ations in which the victim’s or perpetrator’s face was officers who do not handle these cases on a regular basis blurred or concealed in the full image, but the thumbnail may be unaware of the important data that can be depicted an older version that revealed the obscured derived from digital images.
    [Show full text]
  • Digital Negative (DNG) Specification
    Digital Negative (DNG) Ë Specification Version 1.1.0.0 February 2005 ADOBE SYSTEMS INCORPORATED Corporate Headquarters 345 Park Avenue San Jose, CA 95110-2704 (408) 536-6000 http://www.adobe.com Copyright © 2004-2005 Adobe Systems Incorporated. All rights reserved. NOTICE: All information contained herein is the property of Adobe Systems Incorporated. No part of this publication (whether in hardcopy or electronic form) may be reproduced or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of Adobe Systems Incorporated. Adobe, the Adobe logo, and Photoshop are either registered trademarks or trademarks of Adobe Systems Incorporated in the United States and/or other countries. All other trademarks are the property of their respective owners. This publication and the information herein is furnished AS IS, is subject to change without notice, and should not be construed as a commitment by Adobe Systems Incorporated. Adobe Systems Incorporated assumes no responsibility or liability for any errors or inaccuracies, makes no warranty of any kind (express, implied, or statutory) with respect to this publication, and expressly disclaims any and all warranties of merchantability, fitness for particular purposes, and noninfringement of third party rights. Table of Contents Preface . .vii About This Document . vii Audience . vii How This Document Is Organized . vii Where to Go for More Information . viii Chapter 1 Introduction . 9 The Pros and Cons of Raw Data. 9 A Standard Format . 9 The Advantages of DNG . 10 Chapter 2 DNG Format Overview . .11 File Extensions . 11 SubIFD Trees . 11 Byte Order . 11 Masked Pixels .
    [Show full text]
  • One Software Solution. One World of Difference for Your Content
    Datasheet One software Have you heard? There has been a quiet revolution in solution. One world the way color documents are scanned and published on the Web. It is Document Express with DjVu®--a of diff erence for format that has long been preferred by universities your content. and libraries, because it produces dramatically smaller fi les while preserving original quality. Leading companies around the world are now turning to Document Express including Northwest Airlines, Panasonic, Samsung, Sears, Komatsu, and others-- and that’s because Document Express with DjVu is truly in a class by itself. Only Document Express empowers you to send scanned or electronic color documents on any platform, over any connection speed, with full confi dence in the results. Images download quickly, pages retain true design fi delity, and viewers can access and use your content in ways that are impossible with PDF, TIFF, or JPEG. Document Express with DjVu consistently delivers an excellent user experience, every time. About Document Express with DjVu Features Document Express with DjVu (pronounced: déjà vu) uses a highly effi cient document image compression methodology and fi le format. Scientists at AT&T Labs who fi rst de- veloped the DjVu format for color scanning, also found it vastly superior to Postscript or Sample 400dpi color scan PDF formats for transmitting electronic fi les. Document Express with DjVu uses the most advanced document image segmentation ever developed. The document image seg- 46 MB mentation technology enables the Document Express with DjVu format to have the high- est image quality while keeping text separate to maintain the highest legibility possible.
    [Show full text]
  • Making TIFF Files from Drawing, Word Processing, Powerpoint And
    Making TIFF and EPS files from Drawing, Word Processing, PowerPoint and Graphing Programs In the worlds of electronic publishing and video production programs, the need for TIFF or EPS formatted files is a necessity. Unfortunately, most of the imaging work done in research for presen- tation is done in PowerPoint, and this format simply cannot be used in most situations for these three ends. Files can be generally be saved or exported (by using either Save As or Export under File) into TIFF, PICT or JPEG files from PowerPoint, drawing, word processing and graphing programs—all called vector programs—but the results are often poor in resolution (in Photoshop these are shown as having a resolution of 72dpi when opening the Image Size dialogue box: under Image on the menu select Image Size). Here are four ways to save as TIFF (generally the way in which image files are saved) or EPS (gen- erally the way in which files are saved which contain lines or text): Option 1. Use the Program’s Save As or Export option. If it exists, use the Export or Save As option in your vector program. This only works well when a dialogue box appears so that specific values for height, width and resolution can be typed in (as in the programs Canvas and CorelDraw). Anti-aliasing should be checked. Resolution values of 300 dots per inch or pixels per inch is for images, 600 dpi is for images with text and 1200 dpi is for text, graphs and drawings. If no dialogue box exists to type in these values, go to option 2 - 4.
    [Show full text]