c# ghostscript pdf to image: Allow users to attach to pdf form Library application class asp.net windows wpf ajax tutorial

Digital Imaging Tutorial - Presentation

7. Presentation

Key Concepts

introduction

formats/compression

web browsers

network

scaling

monitors

image quality

guidelines

additional reading

CALING

OUTINES AND

ROGRAMS

Institutions have constrained file size by reducing resolution, bit depth, and/or

by applying compression. The goal is to speed delivery to the desktop without

compromising too much image quality. Scaling refers to the process of

creating access versions from a digital master without having to rescan the

source document. The program and scripts used for scaling will affect the

quality of the presentation. For instance, scaling can introduce moiré in

illustrations, such as halftones, when resolution is reduced without attention

paid to screen interference.

Effects of Scaling on Image Quality: The left image is scaled by using a

blur filter, resizing, and reducing the bit depth. The right image is scaled

without the use of blur filter, resulting in moiré.

Scaling programs are also used to reduce the bit-depth of an image and

different processes result in substantially different quality.

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-05.html (1 of 2) [4/28/2003 2:28:22 PM]

Allow users to attach to pdf form - C# PDF Form Data fill-in Library: auto fill-in PDF form data in C#.net, ASP.NET, MVC, WinForms, WPF

Online C# Tutorial to Automatically Fill in Field Data to PDF

create a pdf form to fill out and save; create a writable pdf form

Allow users to attach to pdf form - VB.NET PDF Form Data fill-in library: auto fill-in PDF form data in vb.net, ASP.NET, MVC, WinForms, WPF

VB.NET PDF Form Data fill-in library: auto fill-in PDF form data in vb.net, ASP.NET, MVC, WinForms, WPF

create fillable forms in pdf; create fillable form pdf online

Digital Imaging Tutorial - Presentation

Effects of Scaling Programs: Note the image quality difference between

these two derivatives created by different conversion software.

Several Web sites listed at the end of this section provide helpful information

on scaling programs, optimizing graphics, and choosing file formats to

enhance image quality. Consider also whether the program offers batch

processing and user-defined scripting capabilities, and get a sense of the total

processing times. Minutes spent on one image quickly add up to days, weeks,

and months, depending on the size of your image collection.

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-05.html (2 of 2) [4/28/2003 2:28:22 PM]

VB.NET Image: VB.NET Rectangle Annotation Imaging Control

VB.NET solution is designed to help users create a Able to attach a user-defined shadow to created Allow VB.NET developers to add rectangle annotation to Word

c# fill out pdf form; create a fillable pdf form

VB.NET Image: Image Drawing SDK, Draw Text & Graphics on Image

Allow VB.NET developers to write text on source and graphics drawing function, we attach links to powerful & profession imaging controls, PDF document, image

auto fill pdf form from excel; convert pdf fillable form

Digital Imaging Tutorial - Presentation

7. Presentation

Key Concepts

introduction

formats/compression

web browsers

network

scaling

monitors

image quality

guidelines

additional reading

ONITOR

APABILITIES

User satisfaction with on-screen images will depend on the capabilities of

display systems. In addition to speed of delivery, users are interested in

image quality (legibility and color fidelity adequate to a task); full display of

images on screen; and to a lesser degree accurate representations of the

dimensions of original documents. Unfortunately, given current monitor

technology, meeting all these criteria at the same time is often not possible.

Screen size and pixel dimensions

In contrast to scanners and printers, current monitors offer relatively low

resolution. Typical monitors support desktop settings from a low of 640 x 480

to a high of 1,600 x 1,200, referring to the number of horizontal by vertical

pixels painted on the screen when an image appears.

The amount of an image that can be displayed at once depends on the

relationship of the image's

pixel dimensions (or dpi) to the

monitor's desktop

setting. The percentage of an image displayed can be increased several

ways: by increasing the screen resolution and/or by decreasing the image

resolution.

Increasing screen resolution. Think of the desktop setting as a camera

viewfinder. As the monitor setting dimensions increase, more of an image

may be viewed. The figure below illustrates the viewing area for an image at

various monitor settings.

Increasing Screen Resolution: Viewing area comparison for a 100 dpi

(original document size 8"x10") image displayed at different monitor settings.

The pixel dimension for the image is 800 x 1,000.

Decreasing image resolution. One can also increase the amount of an image

displayed by reducing the resolution of the image through scaling. This figure

illustrates the relationship of a monitor's desktop setting at 800 x 600 to an

image scaled to various resolutions.

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-06.html (1 of 3) [4/28/2003 2:28:23 PM]

VB.NET TIFF: VB.NET Code to Scan Document into TIFF Image File

document is scanned by a physical scanner device, users need to TIFF file in VB.NET image application; Allow VB.NET Here we attach a link which can lead you to

convert pdf form fillable; convert excel spreadsheet to fillable pdf form

Digital Imaging Tutorial - Presentation

Balancing Legibility and Completeness: Displayed at 200 dpi on a 800 x

600 monitor, one can only see a small portion of the page (left). At 60 dpi, the

whole page is fully displayed, but at the expense of legibility (bottom-right).

Scaling the image to 100 dpi offers a compromise by maintaining legibility and

limiting scrolling to one dimension (top-right).

You can calculate the percent of display if you know the following variables:

1) document dimensions and image dpi, or pixel dimensions of image, and 2)

desktop setting.

Calculating percentage displayed

Enter document dimensions in inches:

(width) and

(height) and enter resolution of image:

dpi

Enter image pixel dimensions

horizontal

vertical

Screen size % displayed % width displayed % height displayed

640 x 480

800 x 600

1024 x 768

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-06.html (2 of 3) [4/28/2003 2:28:23 PM]

Calculate!

Reset

Digital Imaging Tutorial - Presentation

Dimensional Fidelity

At times, it may be important to represent an image on-screen at the actual

size of the original scanned document. This can only be achieved when the

digital image resolution equals the monitor's resolution (dpi). The Blake

Archive Project has developed a Java applet, called the

Image Sizer, for

representing images at the actual size of the original.

Reality Check

If representation of dimensional fidelity on-screen is important,

what is the likely impact on image quality?

Image quality will not be affected, only the size of the

image

Image quality will often increase, as the document will be

presented at its native size with details fully presented

Image quality will often decline as the screen resolution is

typically lower than the digital image resolution

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-06.html (3 of 3) [4/28/2003 2:28:23 PM]

Check Answer

Digital Imaging Tutorial - Presentation

7. Presentation

Key Concepts

introduction

formats/compression

web browsers

network

scaling

monitors

image quality

guidelines

additional reading

N-SCREEN

MAGE

UALITY

We have noted the effects of various scaling programs and routines on image

quality. Two other factors should be considered as well:

Is the resolution of the image sufficient to ensure legibility or support

detailed study of an image?

Can color and tone be conveyed effectively?

Legibility of Text

As we have seen, legibility and completeness often conflict. For instance,

when an 8 x 10-inch text-page scanned at 200 dpi is scaled to fit on a monitor

set to 800 x 600, over 90% of the pixels have been discarded. The image fits,

but the text may no longer be readable.

Cornell has developed a benchmarking formula for the display of text-based

materials that correlates image quality, resolution, and the required level of

detail:

Benchmarking On-Screen Legibility Formula

dpi = QI/(.03h)

QI = dpi x .03h

h = QI/(.03dpi)

In the formula, dpi refers to the resolution of an image (not to be confused

with the monitor's dpi); h refers to the height of the smallest character in the

original (in mm); and QI refers to levels of legibility (Note: if h is measured in

inches, multiply by 25.4 before using formula). This formula presumes that

bitonal images are presented with 3 bits or more of gray and that filters and

optimized scaling routines improve image presentation. Using this formula,

establish your own levels of acceptable quality. Cornell benchmarks

readability at a QI of 3.6, although 3.0 often suffices for cleanly produced text,

particularly if it has been scanned in grayscale or color.

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-07.html (1 of 2) [4/28/2003 2:28:24 PM]

Digital Imaging Tutorial - Presentation

Reality Check

A 4 x 5-inch text page contains characters as small as 1mm in height

and has been scanned at 600 dpi-1bit. At what resolution can you

scale this image for on-screen presentation and still maintain

character legibility (at a QI of 3.6)?

dpi

At that resolution, what percentage of your document could be

displayed on a monitor set to 800 x 600?

Color and Tone

Presenting

color and tone depends on monitor and system capabilities. Color

appearance is most problematic since it is affected by different browsers,

monitor settings, and transfer between color spaces.

Several Web sites provide useful information on Web palettes for access (see

additional reading). Some recommend using file formats such as PNG, which

supports both a Web-safe palette and sRGB, designed to ensure color

consistency across platforms. Others are including grayscale/color targets

with the images to enable the end user to adjust the color. Still others,

including the

National Archives and the

Denver Public Library, have

developed monitor adjustment targets to help users calibrate their monitors.

Monitor Adjustment: This portion of the

NARA Monitor Adjustment Target

illustrates the full range of tones that a computer monitor can represent when

set to 256 or more colors (8 bits or higher). The shades should be just

distinguishable from one another. Courtesy of the National Archives and

Records Administration.

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-07.html (2 of 2) [4/28/2003 2:28:24 PM]

Check Answer

Digital Imaging Tutorial - Presentation

7. Presentation

Key Concepts

introduction

formats/compression

web browsers

network

scaling

monitors

image quality

guidelines

additional reading

UIDELINES

To see what some institutions recommend for display, click on:

Table: Representative Institutional Requirements for Access

DDITIONAL

EADING

Anne R. Kenney, "Digital Benchmarking for Preservation and Access," in

Moving Theory into Practice: Digital Imaging for Libraries and Archives,

Mountain View, CA : Research Libraries Group, 2000; pp. 24-60

http://www.rlg.org/preserv/mtip2000.html

John Price-Wilkin, "Enhancing Access to Digital Image Collections: System

Building and Image Processing," in Moving Theory into Practice: Digital

Imaging for Libraries and Archives, Mountain View, CA: Research Libraries

Group, 2000; pp.

http://www.rlg.org/preserv/mtip2000.html

Color and Tone

Lynda Weinman, "The Browser Safe Color Palette,"

http://www.lynda.com/hex.html and

http://the-light.com/netcol.html. Both of

these have links to other useful sites on browser palettes and other Web

graphics information.

Digital Images in Multimedia Presentation, "Image Manipulation and

Preparation,"

http://www.tasi.ac.uk/advice/using/dimpmanipulation.html

The Bandwidth Conservation Society,

http://www.tbcr.org/

Scaling Routines and Programs

Patrick J. Lynch and Sarah Horton, "Web Style Guide,"

http://info.med.yale.edu/caim/manual/contents.html

Wotsit's Graphic File Formats

http://www.wotsit.org/search.asp?s=graphics

Anne R. Kenney and Louis H. Sharpe II, Illustrated Book Study: Digital

Conversion Requirements of Printed Illustrations, 1999,

http://lcweb.loc.gov/preserv/rt/illbk/ibs.htm

TASI, "DIMP WWW - Image Incorporation Case Study,"

http://www.tasi.ac.uk/advice/using/web_case.html

http://www.library.cornell.edu/preservation/tutorial/presentation/presentation-08.html (1 of 2) [4/28/2003 2:28:25 PM]

Digital Imaging Tutorial - Digital Preservation

8. Digital Preservation

Key Concepts

definition

challenges

technical strategies

organizational

strategies

additional reading

EFINITION

The goal of digital preservation is to maintain the ability to display, retrieve,

and use digital collections in the face of rapidly changing technological and

organizational infrastructures and elements. Issues to be addressed in digital

preservation include:

Retaining the physical reliability of the image files, accompanying

metadata, scripts, and programs (e.g., make sure that the storage

medium is reliable with back-ups, maintain the necessary hardware

and software infrastructure to store and provide access to the

collection)

Ensuring continued usability of the digital image collection (e.g.,

maintain an up-to-date user interface, enable users to retrieve and

manipulate information to meet their information needs)

Maintaining collection security (e.g., implement strategies to control

unauthorized alteration to the collection, develop and maintain a rights

management program for fee-based services)

Although this section is one of the last of the tutorial, issues associated with

longevity need to be discussed at the onset of any imaging initiative. Many of

the issues that become impediments to long-term preservation are rooted in

early decisions centering on selection and conversion. Digital preservation

decisions and strategies should be developed as an integral part of a digital

imaging initiative as many decisions will be closely coupled with an

institution's long-term retention plans.

http://www.library.cornell.edu/preservation/tutorial/preservation/preservation-01.html [4/28/2003 2:28:26 PM]

Digital Imaging Tutorial - Digital Preservation

8. Digital Preservation

Key Concepts

definition

challenges

technical strategies

organizational

strategies

additional reading

IGITAL

RESERVATION

HALLENGING

Challenges are multi-faceted and can be grouped into two categories:

Technical Vulnerabilities

Storage media, due to physical deterioration, mishandling, improper

storage, and obsolescence.

File formats and compression schemes, due to obsolescence or over-

reliance on proprietary and unsupported file and compression formats.

Integrity of the files, including safeguarding the content, context, fixity,

references, and provenance.

Storage and processing devices, programs, operating systems,

access interfaces, and protocols that change as technology evolves

(often with limited backward compatibility).

Distributed retrieval and processing tools, such as embedded Java

scripts and applets.

Organizational and Administrative Challenges

Insufficient institutional commitment to long-term preservation

Lack of preservation policies and procedures

Scarcity of human and financial resources

Varying (and asynchronous) stakeholder interests in the creation,

maintenance, and distribution of digital image collections

Gaps in institutional memory due to staff turnover

Inadequate record keeping and administrative metadata

Evolving nature of copyright and fair-use regulations that apply to

digital collections

http://www.library.cornell.edu/preservation/tutorial/preservation/preservation-02.html [4/28/2003 2:28:27 PM]

Documents you may be interested

c# ghostscript pdf to image : Allow users to attach to pdf form Library application class asp.net windows wpf ajax tutorial_English10-part1084