جمهورية العراق / وزارة التعليم العالي والبحث العلمي
جامعة القادسية / كلية علوم الحاسوب وتكنولوجيا المعلومات
قسم الحاســـــــوب
بحث مقدم الى
الى كلية علوم الحاسوب وتكنولوجيا المعلومات- جامعة القادسية
وهو جزء من متطلبات نيل درجة البكالوريوس علوم في الحاسوب
من قبل الطالبة
رغدة راضي هادي
إشراف
م.م. علاء عبد المحسن
1438ه 2017 م
بسم الله الرَّحْمَنِ الرَّحِيـــــــمِ
(رَ ب اشْرَحْ لِّي صَدْرِّي* وَيَسرْ لِّي
أَمْرِّي* وَاحْلُلْ عُقْدَةً من لسَانِّي *
يَفْقَهُوا قَوْلِّي (
صدق الله العلي العظيم
الاهداء
إلى من يسعد قلبي بلقياها
إلى روضة الحب التي تنبت أزكى الأزهار
أمي
إلى رمز الرجولة والتضحية
إلى من دفعني إلى العلم وبه ازداد افتخار
أبي
إلى من هم اقرب أليّ من روحي
إلى من شاركني حضن ألام وبهم استمد عزتي وإصراري
اخوتي
إلى من آنسني في دراستي وشاركني همومي
تذكاراً وتقديرا أصدق ائي
إلى هذه الصرح العلمي الفتي والجبار
جامعة القادسية
اهدي هذا البحث
شكر وتقدير
لابد لنا ونحن نخطو خطواتنا الأخيرة في الحياة الجامعية من وقفة نعود إلى أعوام قضيناها في رحاب الجامعة مع
أساتذتنا الكرام الذين قدموا لنا الكثير باذلين بذلك جهودا كبيرة في بناء جيل الغد لتبعث الأمة من جديد …
وقبل أن نمضي تقدم أسمى آيات الشكر والامتنان والتقدير والمحبة إلى الذين حملوا أقدس رسالة في الحياة …
إلى الذين مهدوا لنا طريق العلم والمعرفة …
إلى جميع أساتذتنا الأفاضل…….
CONTENTS
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1 2 2 2 3 3 4 5 5 5 6 6
8 8 9 9 10 10 11 11 12 13 |
Chapter One
1-1 watermark 1-2 History 1-3 Processes 1-3-1 Dandy roll processP 1-3-2 Cylinder mould process 1-3-3 On postage stamps 1-4 Uploading images 1-5 Procedure to upload 1-6 Find previously uploaded images 1-6-1 Updating existing image 1-7 Technical aspects 1-8 Submitting the information Chapter TWO 2-1 IMAGE 2-2 Characteristics 2-3 Imagery (literary term 2-5 Explanation stretch images 2-5-1 JPEG 2-5-2 GIF 2-5-3 PNG 2-5-4( PSD) Photoshop 2-5-5 TIFF 2-5-6 EPS
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INTRODUCTION
With onset of the World Wide Web, authors of digital media can easily distribute their works by making them available on Web pages or other public forums. Anyone having access to those forums can copy the author’s media. By the nature of digital media, a copy is an exact, perfect duplicate of the original. This brings to front a potential problem. How do authors claim ownership rights of such digital media if multiple persons have exact copies?1 One method is to embed additional information and only distribute the media that contains this additional information. The embedded information is known as a watermark can provide, for example, information about the media, the author, copyright, or license information.
Interest in digital watermarks has grown out of an increasing interest in intellectual property and copyright
protection. Digital watermarks may be perceptible (visible) or imperceptible (invisible) to human vision.
Visible watermarks, by nature, are more intrusive to the media and act to deter theft of the media, such as a
warning sign announces an alarm system even if one does not exist. Examples of such watermarks can be
seen easily on most network television stations by the station’s logo in the corner of the viewable screen.
These watermarks are typically confined to an area of the image, which is less intrusive to the overall image. Attackers have a visible target and can remove the watermark by cropping the image.
CHAPTER ONE
1-1watermark
A watermark is an identifying image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations in the paper. Watermarks have been used on postage stamps, currency, and other government documents to discourage counterfeiting. There are two main ways of producing watermarks in paper; the dandy roll process, and the more complex cylinder mould process .
Watermarks vary greatly in their visibility; while some are obvious on casual inspection, others require some study to pick out. Various aids have been developed, such as watermark fluid that wets the paper without damaging it. A watermark is very useful in the examination of paper because it can be used for dating, identifying sizes, mill trademarks and locations, and determining the quality of a sheet of paper.
The word is also used for digital practices that share similarities with physical watermarks. In one case, overprint on computer-printed output may be used to identify output from an unlicensed trial version of a program. In another instance, identifying codes can be encoded as a digital watermark for a music, video, picture, or other file.
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1-2 History
Watermarks were first introduced in Fabriano, Italy, in 1282.
Digital image watermarking is actually a derivative of Steganography, the ages-old practice of covertly transmitting a message from one party to another, typically used by governments and spy organizations. The earliest recorded use of such a method is mentioned in the Histories of Herodotus, where Histiaeus used the scalp of a slave to convey a secret message through hostile territory in the hopes of inciting a revolt against the Persians (Katzenbeisser, 3). The slave’s head was shaven and tattooed with the secret message. After sufficient time had passed that his hair had regrown, the slave was sent on his mission, passing through Persian territory without arousing suspicion. When he arrived at his destination, his head was re-shaven to reveal the message.
Further examples, both in fiction and in history, can be found in more modern times. In Mother Night, author Kurt Vonnegut writes about a fictional World War II spy, Howard W. Campbell, Jr., who passes information from American spies in Germany to intelligence agents in the United States by steganographic means. Campbell is the narrator of a propaganda program on a German radio broadcast, where he delivers regular denouncements of the United States to anyone listening. All the while, unbeknownst to the German government, Campbell is also broadcasting a subtext of intelligence information by the placement of pauses, coughs, and mispronunciations in the overt message.
As these two examples have endeavored to illustrate, the covert transmission of information by steganographic means has been practiced for most of the recorded history of western civilization. In certain respects steganography and watermarking are very similar in that both are concerned with the unnoticeable transmission of data in some sort of overt carrier (a digital image in the case of watermarking). There are, however, a number of important dissimilarities that make watermarking a discipline of its own. First, and perhaps most importantly, is that steganography is typically practiced between a source and a unique receiver in a one-to-one relationship, whereas watermarking is practiced between a source and many receivers in a one-to-many relationship (Katzenbeisser, 97). Furthermore, methods of watermarking typically adhere to the Kerckhoff principle of cryptography, where one assumes that attackers know the watermarking algorithm, relying instead on a
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mutually agreed upon key for security. The security of steganography, as
should be clear from either of the two examples presented here, lies almost entirely in the secrecy of the algorithm or method and thus is in direct conflict with Kerckhoff’s principle. This is not to say that the secret message could not be encrypted before its transmission, but rather that the existence of the secret message is protected only by the secrecy of the stenographic method.
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1-3-1 Dandy roll process
Traditionally, a watermark was made by impressing a water-coated metal stamp or dandy roll onto the paper during manufacturing. The invention of the dandy roll in 1826 by John Marshall revolutionised the watermark process and made it easier for producers to watermark their paper.
The dandy roll is a light roller covered by material similar to window screen that is embossed with a pattern. Faint lines are made by laid wires that run parallel to the axis of the dandy roll, and the bold lines are made by chain wires that run around the circumference to secure the laid wires to the roll from the outside. Because the chain wires are located on the outside of the laid wires, they have a greater influence on the impression in the pulp, hence their bolder appearance than the laid wire lines.
This embossing is transferred to the pulp fibres, compressing and reducing their thickness in that area. Because the patterned portion of the page is thinner, it transmits more light through and therefore has a lighter appearance than the surrounding paper. If these lines are distinct and parallel, and/or there is a watermark, then the paper is termed laid paper. If the lines appear as a mesh or are indiscernible, and/or there is no watermark, then it is called wove paper. This method is called line drawing watermarks.
1-3-2 Cylinder mould process
Another type of watermark is called the cylinder mould watermark. A shaded watermark, first used in 1848, incorporates tonal depth and creates a greyscale image. Instead of using a wire covering for
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the dandy roll, the shaded watermark is created by areas of relief on the roll’s own surface. Once dry, the paper may then be rolled again to produce a watermark of even thickness but with varying density. The resulting watermark is generally much clearer and more detailed than those made by the Dandy Roll process, and as such Cylinder Mould Watermark Paper is the preferred type of watermarked paper for banknotes, passports, motor vehicle titles, and other documents where it is an important anti-counterfeiting measure.
1-3-3 On postage stamps
In philately, the watermark is a key feature of a stamp, and often constitutes the difference between a common and a rare stamp. Collectors who encounter two otherwise identical stamps with different watermarks consider each stamp to be a separate identifiable issue. The “classic” stamp watermark is a small crown or other national symbol, appearing either once on each stamp or a continuous pattern. Watermarks were nearly universal on stamps in the 19th and early 20th centuries, but generally fell out of use and are not commonly used on modern U.S. issues, but some countries continue to use them.
Some types of embossing, such as that used to make the “cross on oval” design on early stamps of Switzerland, resemble a watermark in that the paper is thinner, but can be distinguished by having sharper edges than is usual for a normal watermark. Stamp paper watermarks also show various designs, letters, numbers and pictorial elements.
The process of bringing out the stamp watermark is fairly simple. Sometimes a watermark in stamp paper can be seen just by looking at the unprinted back side of a stamp. More often, the collector must use a few
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basic items to get a good look at the watermark. For example, watermark fluid may be applied to the back of a stamp to temporarily reveal the watermark.
Even using the simple watermarking method described, it can be difficult to distinguish some watermarks. Watermarks on stamps printed in yellow and orange can be particularly difficult to see. A few mechanical devices are also used by collectors to detect watermarks on stamps such as the Morley-Bright watermark detector and the more expensive Safe Signoscope. Such devices can be very useful for they can be used without the application of watermark fluid and also allow the collector to look at the watermark for a longer period of time to more easily detect the watermark.
- Uploading images
- clearly establishing that the copyright status of each intended upload is appropriate for a free-content encyclopedia; and then
- uploading the image with clear labeling as to its origin and copyright status.
Here is a brief synopsis of the image requirements:
Allowed copyright statuses include (in descending order of desirability):
- Public Domain (expired copyright or public from inception)
- One of various licenses listed in this Wikipedia resource page
- Claimed as fair use
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1-5 Procedure to upload
Only logged in users with autoconfirmed accounts can upload
images (meaning that the account must be at least four days old, and the user must have made at least ten edits). If you do not have an account, or you have not been auto confirmed yet.
You can upload an image by using the Upload file link on the left side of the main page under Toolbox (which is a link to Special:Upload). On most browsers, you will see a “Browse…” button, which will bring up your operating system’s standard file open dialog. Choosing a file will fill the name of that file into the text field next to the button. You must also check the box affirming that you are not violating any copyrights by uploading the file. Press the “Upload” button to finish the upload. This may take some time if you have a slow Internet connection.
- Find previously uploaded images
- To view or search images previously uploaded directly , go to the list of uploaded images.
- Uploads and deletions are logged on the upload log.
- Many images can be categorized in one of the subcategories of Category images by subject or its parent category Category. You may want to check there to see if an image already exists and has been categorized. You might need to poke around the category hierarchy a bit.
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1-6-1 Updating existing image
To update an existing image, for example an infographic with out of date information, go to that image file description page and find the
link that says “upload a new version of this file”, which opens a wizard to upload the new version. Describe only the changes that you have made to the file, as the general description of the file (including licensing, etc) will remain from before. The new version will now automatically be accessed by the pages that link to the file, but will keep the old version in the “File History” section of the file description page.
After uploading a new version of an image to the same image name you often need to bypass your browser cache to see the new image. This also fixes the oddity that the new image might show on the image page, but with the old image size. Sometimes after uploading a new version of an image the thumbnails in articles still show the old image even if you have bypassed your browser cache (which is especially ugly if the new image is of a different size). Then you need to purge the image page.
1-7 Technical aspects
The preferred formats are JPEG for photographic images, SVG for drawings and line-art illustration, PNG for non-vector graphic iconic images, Ogg Vorbis for sound and Ogg Theora for video. Please name your files descriptively to avoid confusion (see below). To
include the image in an article, use a link in the form [[File:filename.jpg]] or [[File:filename.png|alt text]] or [[File:filename.ogg]] for sounds. To include an image as a thumbnail, use [[File:filename.jpg|thumb|Caption]].
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1-8 Submitting the information
After entering the information, submitting it will upload the image and save the summary. There is no preview, as there is for editing articles. Nevertheless, the Sandbox or a user page can be used to view and edit summaries before the image is uploaded, and after uploading, you can still click the edit button and make changes to the summary and the license, if you have made a mistake.
If there is already a file that was uploaded with the Destination Filename you chose, then you are given the options to save anyway and overwrite the old file (although it will remain in the image history) or returning to the upload form and entering a different filename.
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CHAPTER TWO
2-1 IMAGE
An image is an artifact that depicts visual perception, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person, thus providing a depiction of it.
2-2 Characteristics
Images may be two-dimensional, such as a photograph or screen display, or three-dimensional, such as a statue or hologram. They may be captured by optical devices – such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water.
The word ‘image’ is also used in the broader sense of any two-dimensional figure such as a map, a graph, a pie chart, or a painting. In this wider sense, images can also be rendered manually, such as by drawing, the art of painting, carving, rendered automatically by printing or computer graphics technology, or developed by a combination of methods, especially in a pseudo-photograph.
A volatile image is one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of a camera obscure, or a scene displayed on a cathode ray tube. A fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or any other digital process.
A mental image exists in an individual’s mind, as something one remembers or imagines. The subject of an image need not be real; it may be an abstract concept, such as a graph, function, or “imaginary” entity. For example, Sigmund Freud claimed to have dreamed purely in aural-
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images of dialogs. The development of synthetic acoustic technologies and the creation of sound art have led to a consideration of the possibilities of a sound-image made up of irreducible phonic substance beyond linguistic or musicological analysis.
A still image is a single static image, as distinguished from a kinetic image (see below). This phrase is used in photography, visual media and the computer industry to emphasize that one is not talking about movies, or in very precise or pedantic technical writing such as a standard.
A film still is a photograph taken on the set of a movie or television program during production, used for promotional purposes.
2-3 Imagery (literary term)
In literature, imagery is a “mental picture” which appeals to the senses. It can both be figurative and literal.
2-5 Explanation stretch images
Image formats are the type of image file … each of these files have the characteristics and some of them similar in characteristics with a slight difference … For example, the extension BMB is the most popular types of image formats has been devised by Microsoft’s standard body images to be in the windows, and the Stretch JPEG / JPG most popular body and the spread is considered especially to view images on the internet, and the body characterized as GIF supports transparency and animated images are used in the web largely because the small size, but they do not give a true picture because the colors are limited.
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2-5-1 JPEG
JPEG body telly for the ferry (Joint Photographic Experts Group) and pronounced “gee-flushing.” The most popular body and the spread is considered especially to view images on the Internet. And have the following advantages :
Using JPEG compression mechanism variable, where you can control the degree of pressure storage, to get the size of Vail appropriately, so that you can get a very small file size, but of course with the weakness in the quality of the image .
Commission supports JPEG depth chromatic system up to 24-bit (16 million colors) give any true picture
A disadvantage that it does not support transparency and motion JPEG file when you save it retains the colors of the image as it is, because as we mentioned supports 16 million colors
As for transparency, it does not support transparency Thou shalt therefore keep a white background.
2-5-2 GIF
Body GIF is the abbreviation for the phrase (Graphics Interchange Format) and pronounced “jiff” is widely used on the Web this body store up to 256 color no limited colors as the picture is composed of millions of hues, the applications such as Adobe Photoshop when you save the image in the form of GIF choose the best of these colors to represent everyone. When the display, each pixel in the image takes one of the available colors within the 256 color used with the written arts such as cartoons,
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drawings, charts, logos, texts, and not for your photos.
Added to the new style GIF 89a some advantages and possibilities, which include:
- Make a transparent background image
- Animations make the picture
When you save the file GIF it nearly colors to one of the available colors within the 256 color As for the transparency it supports transparency, but one level.
2-5-3 PNG
Body PNG Telly’s (Portable Network Graphics) and pronounced “ping”, developed to replace the body GIF replace similar PNG with body GIF in being used pressure conservative mechanism body (compression without loss of detail), and surpass
them in the availability of some features that are not available in the body GIF this includes the 254 level of transparency, while the GIF supports only one level, the largest as well as the control Badrhh brightness of the image, and support for the system 48 bits per pixel GIF supports 8-bit only, ie 256 color support body PNG – 16 million colors while the body GIF supports 256 colors when you save a PNG file, it is characterized by the kind where 254 includes the level of transparency of the transparent.
2-5-4( PSD) Photoshop
When processing the image using the famous program Photoshop Adobe Photoshop, there are a lot of advantages that help during editing,
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such as the layers (Layers), so the Photoshop its own local body to save
the image file while you work called PSD, this body record all procedures and modifications induced by the image that, and then you can return to it and re-edited. Upon completion of treatment, you should save the image to the more common entity, to facilitate the trading process between applications, such as JPEG, TIFF or BMP.
When you save the file, it retains the PSD layers means the possibility of the amendment to the file, but this type does not open, but in Photoshop.
2-5-5 TIFF
Telly’s body TIFF (Tag Image File Format) and uttered “Tiv” designed by stomping Aldus Corporation originally to save the following images from the scanner (Scanner) or treatment programs. This body has spread widely, and spread Khaihnql images without having to be tied to a specific scanner or printer or processing program. TIFF body enjoys a wide reputation also with professional publishing applications. There are several versions of the body called TIFF expansions extensions, here are some of the problems when you try to download one from the other way. Some expansions handle pressure mechanism of the kind LZW that does not weaken at all the picture. TIFF body supports color depth 24-bit maximum of the equivalent of 16 million colors.
When you save a TIFF file, it retains Balerat
It also opens across other applications.
BMP
BMP, which pronounces the letters “B-M-P characters”, using the
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mechanism of Windows in the distribution of bits. And allowing Windows display Alaptmap on any display device. Commonly used in most applications, it does not use a pressure mechanism, a negotiable on all devices.
2-5-6 EPS
Telly’s body EPS (Encapsulated PostScript) and pronounces the letters “E-P-S characters.” Commission developed the Adobe for printers that accept applets used. This Alvaellat generally consists of two parts. Part I is a text description of the printer it shows how it should be the form of the printed image. Part Two additional PICT image of the body used for display on the screen. After you save the image on the EPS body, it can be downloaded by other applications and make scaling it (change the standards). However, the content of these Alvaellat N for re-editing only by certain applications such as Adobe Illustrator. Usually does not save the images on the EPS body only after the completion of the completely processed, and preparing to be sent to the publishing houses.
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