PDF Technology: Overview

Acrobat 4.0 has finally come out. A compelling feature is the support for ICC color. This new feature has excited the industry. The long-awaited features of the industry are now very easy for Acrobat 4.0.

Today, the rapid development of high technology and IT has made us incredible about many technologies in the industry today. Looking back over the past decade, a large number of prepress and print jobs can be achieved using a variety of technologies and equipment. Today, this way of working looks old and outdated. In the past ten years, the prepress and printing industries have undergone earth-shaking changes. Various new products and technologies have appeared like bamboo shoots. They have or are changing the printing and publishing industry. Its influence is unprecedented in the entire printing history. of. Many desktop applications and many hard devices we use today are completely new things ten or twenty years ago!

For example, when it comes to color management in the past, it is nothing but a scanner operator, a print mechanic who adjusts colors with his eyes, and a control bar for color control. In the entire prepress processing process, he obtains high quality colors. With regard to subjective experience, of course, the color between work and homework will certainly be biased. Today, the function of color management has undergone profound changes. It has been integrated into the entire workflow. From the software that generates and exports pages to the input and output hard devices (such as monitors), color management plays an important role.

It now appears that desktop scanning software, digital editing software, typography, layout, trapping, preflight, and color management software used in the printing and publishing industry are completely unstable. Now we have one more choice for generating and transferring files, namely the famous PDF format (portable file format).


Quietly entering the field of printing and publishing In the past few years, Adobe Acrobat and PDF files have been systematically entered into the field of professional photocopying, but since the pre-4.0 version of Acrobat cannot provide the required color support functions, it is used in the printing and publishing industry. Very limited. This flaw has now greatly improved, and Acrobat 4.0 can better meet the needs of professional publishing and printing. The recently launched Acrobat 4.0 is worth reviewing its application value in the printing and publishing industry. In particular, its color function is considered from the perspective of professional printing and publishing. Therefore, it is more professional.

What is PDF for? What is the original intention of designing PDF files? The answer is to make it easy to transfer files between computers. PDF files can be read using free downloadable reader files. It is independent of the computer platform and can be used on different computer platforms. Today, PDF files are gradually becoming a more general standard for hardware/software output files. With Acrobat reading software, any end user can read the PDF file and then output it in hard copy. PDF files can be printed out on various printers.

PDF files have several advantages over proprietary application file formats used by Adobe PageMaker and Quark XPress. First, usually the fonts used in PDF files are built into PDF files. Each type of built-in font will increase the volume of 30-40K file information; the font can also be set by on-demand setting, that is, only in the job. The required characters are set in the file. This way the file is smaller, but it will limit the editing work in the later stage. Second, several compression techniques provided by the PDF file format make the file smaller and therefore more suitable for electronic transmission. Some of these compression technologies may differ from many prepress compression technologies, but these compression technologies work in a transparent manner.


Four ways to use PDF
Adobe divides the main uses of PDF files in four ways: First, download. That is, the file is downloaded in PDF format when downloaded from an online resource. Second, distribute. The files are distributed on CD. Third, directly output to the output device, ie PDF files are sent directly to inkjet, laser printers or digital copy machines. Fourth, PDF files are sent directly to traditional presses or digital presses. The above four applications require different setting options for different applications, such as resolution, color space selection, and built-in font settings, when generating Postscript and PDF. PDF files used for printing must be correct, and PDF files used in the publishing and printing industries are more complex and archived than PDF files in online browsing applications.

The function is getting better Editing PDF files is not an easy task, which is worse than the proprietary format. Acrobat Exchange now offers a "Touch Up" tool that allows for minimal text editing of text, such as modifying fonts and changing character sizes. Another difficulty faced by PDF users is the difficulty in editing images. For more editing features, try out PitStop provided by EnFocus, an Acrobat Exchange plug-in for Mac, Windows 95/98/NT. PitStop has now been upgraded to version 4.0, which provides more text editing capabilities, color correction, moving and changing objects in the page. In addition, objects can be copied and pasted between PDF files.
Many software developers have now successfully developed plug-ins for Acrobat Exchange. These plug-ins greatly enhance the functionality of Exchange. In addition to EnFocus's PitStop, there are Lantana Research Cracker jack plug-ins, which provide features such as color separations. Functionality, support registration and clip markings;

This year, Adobe introduced Acrobat 4.0 and upgraded the PDF 1.2 version (for Acrobat 3.0) to version 1.3 (for Acrobat 4.0). These products are already visible in the software market. Acrobat 4.0 runs on Mac, Pentium 486PC (Windows 95, 98, NT can be). Acrobat 4.0 and PDF 1.3 are major breakthroughs because they greatly enhance the capabilities of PDF files, not just for publishing.

Acrobat 4.0 and PDF version 1.3 provide more powerful support for TrueType fonts, significantly improved support for color and color output (including color management), enhanced editing capabilities for text and graphics, and support Double-byte text. Of course, the functionality of the TouchUp tool has also been greatly improved. Now that the page supports 200200 inches, it supports large format printers.

Just as PDF1.2 builds on PostscriptLevel2, PDF1.3 builds on PostscriptLevel3. Postscript provides 1024 shades of gray, while PostscriptLevel2 supports 256 shades of gray. PDF files generated by Acrobat 4.0 run on Postscript3. These files are also compatible with Level2 RIP.


Acrobat common sense
Acrobat is actually an application package. People simply call Acrobat Exchange, the core application software of Acrobat software package, Acrobat, which can be exported to many devices. Postscript files can be saved in PDF format and can be implemented in one or two steps.

Acrobat Capture
Acrobat Capture works with a scanner to perform OCR (optical character recognition) work in files and then convert the data to PDF format. Acrobat Web Capture is now available only for the Windows operating system. It can download HTML files and then convert them to PDF files, while the file still retains Web links.

PDF Maker
PDF Maker is only suitable for Windows operating system. It can generate PDF files directly from files generated by Microsoft Word, Excel, and PowerPoint.

Reader4.0
Acrobat Reader 4.0 can run directly on PPC Mac, Windows 95/98/NTPC machines, it can read and print any PDF file.

The production of PDF
Acrobat Distiller software provides some shortcuts, but generating a PDF file is usually a two-step operation. The first step is to generate a Postscript file. In fact, this is a function supported by all desktop applications. The second step is to “concentrate” Postscript files into PDF files.
For some application software, such as PageMaker, you can generate PDF files from PageMaker's special files in one step, because there is no need to pause between the first step and the second step, so one step can be generated. Distiller is currently bundled with PageMaker. Quark offers a Beta XTension for XP4 that can import and export PDF files.

In the first half of this year, Adobe launched InDesign, a design and imposition software that can also generate PDF files directly, eliminating the Distiller software.

For Acrobat Distiller software, users can use it to read Postscript files, "concentrate" files and write PDF files, and then PDF files can be widely read. For simple and less complex jobs, only a small amount of work is required to output them to PostscriptLevel2 or PostscriptLevel3 image output machines. When generating a Postscript file, you can make some important settings for the font; when generating a PDF file, you can set options including resolution and color copying. For information on how to set it, refer to Adobe's technical reference book or visit Adobe's website.


This is not a comparison
Prior to Acrobat 4.0, the biggest drawback was that it was prone to errors during the "enrichment" of the file. This is because the default settings in the previous version of Distiller were for screen browsing and not for professional graphic information. Copying, the resolution of all the many PDF files is extremely low, and the color information built into the file is RGB instead of CMYK.
Acrobat 4.0 solves these problems with three default settings. The first is a setting for screen browsing; the second printing setting is printed on a digital press. The last file set is compressed so that it is suitable for print copying. The user can change the above three preset default values ​​to achieve the desired, and the changed default settings allow other users to share. Acrobat 4.0 also fully supports the ColorSync color management system on the Mac.

One of the distinguishing features of Distiller 4.0 is that it has a very large working options dialog box. Users can choose from the Screen Optimized, Print Optimized, Press Optimized settings, or generate user-defined options. Acrobat 4.0 allows you to insert, remove, rearrange, cut, replace pages, and more.
In previous versions of Acrobat, the ability to edit PDF pages was very limited, and text editing could only edit one line at a time. As for editing images, it is simply a fantasy. With the introduction of Acrobat 4.0, images can be edited or even replaced as needed, and all pages of the PDF file can be extracted into Illustrator at a time, and pages can be edited and replaced later.

Adobe also made changes to the user interface, expanded the Acrobat tool, and made some adjustments to keyboard shortcuts. Now there is a new vertical toolbar in Acrobat 4. A navigation bar on the left side of the page display is used to display bookmarks. Thumbnails or annotations, etc., horizontal and vertical toolboxes also have new changes.

In previous versions of Acrobat, the handling of pages containing TrueType fonts was a headache, although jobs could be exported without any changes to the archives, but once the changes needed, the fonts could not be selected at all and could not be edited. Acrobat4 solves this problem very well.

In the previous Acrobat 4 version, the serial number of the PDF file page was also a headache, and the page number of the file often did not correspond to the page number of the print file.


The pre-check of key links in the workflow now,