Internel Paper Solution For Computer Graphics
Ans:- Frame Buffer is portion of RAM containing a bitmap that drives a video display
Pixel is a single point in a graphic image. Graphic monitors display picture by dividing the display screen into thousands of pixel, arranged in rows and columns. The pixels are so close together that they appear connected
2) Which are the possible slope values of a Line ?
Ans:-
2) Which are the possible slope values of a Line ?
Ans:-
3) Define concave and convex polygon
Ans:-A convex polygon is defined as a polygon with all its interior angles less than 180 °. This means that all the vertices of the polygon will point outwards, away From the interior of the shape. Think of it as a bulging' polygon. Note that a triangle (3-gon) is a always convex.
A simple polygon that is not convex is called concave, non-convex or reentrant. A concave polygon will always have at least one reflexinterior angle-that is, an angle with a measure that is between 180 degrees and 360 degrees exclusive.
4) Define Major and Minor axis of ellipse ?
Ans:-
Major:- The longest diameter of an ellipse
Minor:- The shortest diameter of an ellipse
5) List out computer input and display device ?
Ans:-
Input Device
- Keyboard.
- Image scanner.
- Microphone.
- Pointing device. Graphics tablet. Joystick. Light pen. Mouse. Optical. Pointing stick. Touchpad. Touchscreen. Trackball.
- Webcam. Softcam.
- Refreshable braille display.
Display device
- Cathode ray tube display (CRT)
- Light-emitting diode display (LED)
- Electroluminescent display (ELD)
- Electronic paper, E Ink.
- Plasma display panel (PDP)
- Liquid crystal display (LCD) ...
-Organic light-emitting diode display (OLED)
6) State the merits of DVST ?
Ans:-
- Less time consuming.
Ans:-
- Less time consuming.
- No refreshing is required because we do not work pixel by pixel.
- Complex pictures can be shown at very high resolution.
7) Cathode ray tube
Ans:- The primary output device in a graphical system is the video monitor. The main element of a video monitor is the Cathode Ray Tube (CRT)
7) Cathode ray tube
Ans:- The primary output device in a graphical system is the video monitor. The main element of a video monitor is the Cathode Ray Tube (CRT)
8) Raster Scan
Ans:- In a raster scan system, the electron beam is swept across the screen, one row at a time from top to bottom. As the electron beam moves across each row, the beam intensity is turned on and off to create a pattern of illuminated spots.
9) Random Scan (Vector Scan)
Ans:- In this technique, the electron beam is directed only to the part of the screen where the picture is to be drawn rather than scanning from left to right and top to bottom as in raster scan. It is also called vector display, stroke-writing display, or calligraphic display
10) Application of Graphics System
Ans:- In a raster scan system, the electron beam is swept across the screen, one row at a time from top to bottom. As the electron beam moves across each row, the beam intensity is turned on and off to create a pattern of illuminated spots.
9) Random Scan (Vector Scan)
Ans:- In this technique, the electron beam is directed only to the part of the screen where the picture is to be drawn rather than scanning from left to right and top to bottom as in raster scan. It is also called vector display, stroke-writing display, or calligraphic display
10) Application of Graphics System
Ans:-
A) Presentation Graphics
-> The software includes functions for creating various types of charts and graphs and for inserting text in a variety of fonts. Most systems enable you to import data from a spreadsheet application to create the charts and graphs. Presentation graphics is often called business graphics.
B) Entertainment
-> Entertainment. One of the main fields of application of computer graphics is thee entertainment industry, in particular computer games and movies. It is assumed that the first film, which began to use computer graphics was the Throne, and the first feature-length fllm created completely using computer was Toy Story.
C) Education And Training
-> Comuter generated models of physical, financial, and economic systems are often used as educational aids. It helps the trainees to understand the operation of the system. Simulators for practice sessions or training of ship captains, aircraft pilots, heavy equipmen toperators, and air traffic-control personnel.
D) Image Processing
-> Image processing is a method to perform some operations on an image, in order to get an enhanced image or to extract some useful information from it. It is a type of signal processing in which input is an image and output may be image or characteristics/features associated with that image.
A) Presentation Graphics
-> The software includes functions for creating various types of charts and graphs and for inserting text in a variety of fonts. Most systems enable you to import data from a spreadsheet application to create the charts and graphs. Presentation graphics is often called business graphics.
B) Entertainment
-> Entertainment. One of the main fields of application of computer graphics is thee entertainment industry, in particular computer games and movies. It is assumed that the first film, which began to use computer graphics was the Throne, and the first feature-length fllm created completely using computer was Toy Story.
C) Education And Training
-> Comuter generated models of physical, financial, and economic systems are often used as educational aids. It helps the trainees to understand the operation of the system. Simulators for practice sessions or training of ship captains, aircraft pilots, heavy equipmen toperators, and air traffic-control personnel.
D) Image Processing
-> Image processing is a method to perform some operations on an image, in order to get an enhanced image or to extract some useful information from it. It is a type of signal processing in which input is an image and output may be image or characteristics/features associated with that image.
11) DDA Algorithm
Ans :-
Digital Differential Analyzer (DDA) algorithm is the simple line generation algorithm which is explained step by step here.
Digital Differential Analyzer (DDA) algorithm is the simple line generation algorithm which is explained step by step here.
Step 1 − Get the input of two end points (X0,Y0)(X0,Y0) and (X1,Y1)(X1,Y1).
Step 2 − Calculate the difference between two end points.
dx = X1 - X0 dy = Y1 - Y0
Step 3 − Based on the calculated difference in step-2, you need to identify the number of steps to put pixel. If dx > dy, then you need more steps in x coordinate; otherwise in y coordinate.
if (absolute(dx) > absolute(dy))
Steps = absolute(dx);
else
Steps = absolute(dy);
Steps = absolute(dx);
else
Steps = absolute(dy);
Step 4 − Calculate the increment in x coordinate and y coordinate.
Xincrement = dx / (float) steps;
Yincrement = dy / (float) steps;
Step 5 − Put the pixel by successfully incrementing x and y coordinates accordingly and complete the drawing of the line.
for(int v=0; v < Steps; v++)
{
x = x + Xincrement;
y = y + Yincrement;
putpixel(Round(x), Round(y));
}
12)Bresenham’s Line Generation
{
x = x + Xincrement;
y = y + Yincrement;
putpixel(Round(x), Round(y));
}
12)Bresenham’s Line Generation
Ans:- Download here
13) Polygon Filing algorithm
Ans:-Download here
14) Application Area of Computer Graphics
Ans:-
There are likely billions of graphic images available on the World Wide Web, and with few exceptions, almost any user can view any of them with no difficulty. This is because all those images are stored in what amounts to a handful of file formats. Before discussing the principal graphics file formats, however, we need to review the two fundamental types of graphics: raster and vector.
Most graphics that we see on-screen, and many that are printed on paper, are actually structured as rectangular grids of pixels or colored dots. A full-color image requires more color information than a black-and-white image. Some types of graphics use geometric functions that allow them to be scaled up or down in size.
JPEG
The Joint Photographic Experts Group created the JPEG standard in 1990 for the efficient compression of photographic images. JPEG allows varying levels of lossy compression, letting you trade off quality against file size. Progressive JPEG is a way to rearrange the graphic data to permit a rough view of the entire image even when only a small portion of the file has been downloaded. The JPEG standard includes 29 distinct coding processes, but not all of them need to be used. If an image has flat areas of single color that transition sharply to contiguous areas, JPEG doesn’t work as well as GIF.
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13) Polygon Filing algorithm
Ans:-Download here
14) Application Area of Computer Graphics
Definition:- Graphic images are stored digitally using a small number of standardized graphic file formats, including bit map, TIFF, JPEG, GIF, PNG; they can also be stored as raw, unprocessed data.
There are likely billions of graphic images available on the World Wide Web, and with few exceptions, almost any user can view any of them with no difficulty. This is because all those images are stored in what amounts to a handful of file formats. Before discussing the principal graphics file formats, however, we need to review the two fundamental types of graphics: raster and vector.
A raster image is like a photo in your newspaper. Look closely and you’ll see it’s made up of equally spaced round dots in several distinct colors. But if you look at an ad featuring a line drawing or, better yet, a banner headline, you won’t see an interrupted line of dots but a solid image bounded by smooth curves. Those are vector graphics. Many graphics are created as vector graphics and then published as raster images.
Most graphics that we see on-screen, and many that are printed on paper, are actually structured as rectangular grids of pixels or colored dots. A full-color image requires more color information than a black-and-white image. Some types of graphics use geometric functions that allow them to be scaled up or down in size.
One final distinction should be made between how an image is stored (its graphic file format) and how it is generated for viewing by the end user.
Most devices that output images, whether they be monitors, TVs or ink-jet printers, actually produce raster output. They create successive minuscule lines, each consisting of a line of dots of different colors (and perhaps sizes) that end up on the final page as both images and letters. Before the advent of modern high-resolution displays, there were CRT devices that actually produced true vector output, but those are mainly history now. So we need to provide our monitors or printers with sequences of all those colored dots. A graphic that is already rasterized will save time and electrons because it doesn’t need further processing by the computer.
BMP
The simplest way to define a raster graphic image is by using color-coded information for each pixel on each row. This is the basic bit-map format used by Microsoft Windows. The disadvantage of this type of image is that it can waste large amounts of storage. Where there’s an area with a solid color, for example, we don’t need to repeat that color information for every new contiguous pixel. Instead, we can instruct the computer to repeat the current color until we change it. This type of space-saving trick is the basis of compression, which allows us to store the graphic using fewer bytes. Most Web graphics today are compressed so that they can be transmitted more quickly. Some compression techniques will save space yet preserve all the information that’s in the image. That’s called “lossless” compression. Other types of compression can save a lot more space, but the price you pay is degraded image quality. This is known as “lossy” compression.
The simplest way to define a raster graphic image is by using color-coded information for each pixel on each row. This is the basic bit-map format used by Microsoft Windows. The disadvantage of this type of image is that it can waste large amounts of storage. Where there’s an area with a solid color, for example, we don’t need to repeat that color information for every new contiguous pixel. Instead, we can instruct the computer to repeat the current color until we change it. This type of space-saving trick is the basis of compression, which allows us to store the graphic using fewer bytes. Most Web graphics today are compressed so that they can be transmitted more quickly. Some compression techniques will save space yet preserve all the information that’s in the image. That’s called “lossless” compression. Other types of compression can save a lot more space, but the price you pay is degraded image quality. This is known as “lossy” compression.
TIFF
Most graphics file formats were created with a particular use in mind, although most can be used for a wide variety of image types. Another common bit-mapped image type is Tagged Image File Format, which is used in faxing, desktop publishing and medical imaging. TIFF is actually a “container” that can hold bit maps and JPEGs and allows (but doesn’t require) various types of compression.
Most graphics file formats were created with a particular use in mind, although most can be used for a wide variety of image types. Another common bit-mapped image type is Tagged Image File Format, which is used in faxing, desktop publishing and medical imaging. TIFF is actually a “container” that can hold bit maps and JPEGs and allows (but doesn’t require) various types of compression.
JPEG
The Joint Photographic Experts Group created the JPEG standard in 1990 for the efficient compression of photographic images. JPEG allows varying levels of lossy compression, letting you trade off quality against file size. Progressive JPEG is a way to rearrange the graphic data to permit a rough view of the entire image even when only a small portion of the file has been downloaded. The JPEG standard includes 29 distinct coding processes, but not all of them need to be used. If an image has flat areas of single color that transition sharply to contiguous areas, JPEG doesn’t work as well as GIF.
JPEG 2000 is a wavelet-based standard designed to supersede the original. It offers improved compression, including lossless compression, and supports multiple resolutions in a single file, but it has only limited support in current Web browsers.
GIF
The Graphic Interchange Format takes an image and re-creates it using a palette of no more than 256 colors. These palettes can be totally different for different images. GIF is a very efficient format that achieves very good compression for nonphotographic images. GIF also permits the creation of animated images by allowing a file to contain several different frames (each with its own palette) and to switch between them with a specified delay. In addition, GIF images are one of the few types that can have a transparent background, meaning that there’s no need to always display a rectangular area.
The Graphic Interchange Format takes an image and re-creates it using a palette of no more than 256 colors. These palettes can be totally different for different images. GIF is a very efficient format that achieves very good compression for nonphotographic images. GIF also permits the creation of animated images by allowing a file to contain several different frames (each with its own palette) and to switch between them with a specified delay. In addition, GIF images are one of the few types that can have a transparent background, meaning that there’s no need to always display a rectangular area.
GIF was once quite popular, but in 1995, it became the centerpiece of a patent dispute that clouded the issue of who could use what. The patent in question was for the LZW lossless compression algorithm; it expired in 2003.
PNG
Portable Network Graphics is a standard developed in 1996 as an alternative to and improvement on GIF, but without the patent issues and palette restrictions. PNG can compress an image more than GIF and supports improved background transparency/opacity but allows only single images, without animation.
Portable Network Graphics is a standard developed in 1996 as an alternative to and improvement on GIF, but without the patent issues and palette restrictions. PNG can compress an image more than GIF and supports improved background transparency/opacity but allows only single images, without animation.
Raw Data
As digital photography becomes ubiquitous and multimegapixel digital cameras grow more common, you may hear more about raw images. Most inexpensive, consumer-grade digicams store images as JPEG files (technically in EXIF format, a form of JPEG) that involve the loss of some detail. This was done initially to keep file sizes small, when flash memory storage was much more expensive than it is now.
As digital photography becomes ubiquitous and multimegapixel digital cameras grow more common, you may hear more about raw images. Most inexpensive, consumer-grade digicams store images as JPEG files (technically in EXIF format, a form of JPEG) that involve the loss of some detail. This was done initially to keep file sizes small, when flash memory storage was much more expensive than it is now.
Some higher-end cameras now offer the ability to save all image information as raw, unprocessed data in a nonstandardized format that takes more storage space but prevents the loss of subtle detail.
Raw images can be edited with professional-grade software and converted to JPEGs for printing or other forms of distribution.
Raster Graphic And Vector Graphic
Raster Graphic
Most images you see on your computer screen are raster graphics. Pictures found on the Web and photos you import from your digital camera are raster graphics. They are made up of grid of pixels, commonly referred to as a bitmap. The larger the image, the more disk space the image file will take up. For example, a 640 x 480 image requires information to be stored for 307,200 pixels, while a 3072 x 2048 image (from a 6.3 Megapixel digital camera) needs to store information for a whopping 6,291,456 pixels.
Since raster graphics need to store so much information, large bitmaps require large file sizes. Fortunately, there are several image compression algorithms that have been developed to help reduce these file sizes. JPEG and GIF are the most common compressed image formats on the Web, but several other types of image compression are available.
Raster graphics can typically be scaled down with no loss of quality, but enlarging a bitmap image causes it to look blocky and "pixelated." For this reason, Vector Graphics are often used for certain images, such as company logos, which need to be scaled to different sizes.
File extensions: .BMP, .TIF, .GIF, JPG
Vector Graphic
Unlike JPEGs, GIFs, and BMP images, vector graphics are not made up of a grid of pixels. Instead, vector graphics are comprised of paths, which are defined by a start and end point, along with other points, curves, and angles along the way. A path can be a line, a square, a triangle, or a curvy shape. These paths can be used to create simple drawings or complex diagrams. Paths are even used to define the characters of specific typefaces.
Because vector-based images are not made up of a specific number of dots, they can be scaled to a larger size and not lose any image quality. If you blow up a raster graphic, it will look blocky, or "pixelated." When you blow up a vector graphic, the edges of each object within the graphic stay smooth and clean. This makes vector graphics ideal for logos, which can be small enough to appear on a business card, but can also be scaled to fill a billboard. Common types of vector graphics include Adobe Illustrator, Macromedia Freehand, and EPS files. Many Flash animations also use vector graphics, since they scale better and typically take up less space than bitmap images.
File extensions: .AI, .EPS, .SVG, .DRW
15) Video Display device
Ans:-A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers. The first computer monitors used Cathode ray tubes (CRTs), which was the dominant technology until they were replaced by LCD monitors in the 21st Century.
Referesh CRT
A cathode ray tube (CRT) is a specialized vacuumtube in which images are produced when an electron beam strikes a phosphorescent surface. Most desktop computer displays make useof CRTs.
The CRT in a computer display is similar to the"picture tube" in a television receiver. A cathode ray tube consists of several basic components, as illustrated below. The electron gun generates an arrow beam of electrons. The a nodes accelerate the electrons. Deflecting coils produce an extremely low frequency electro-magnetic field that allows for constant adjustment of the direction of the electron beam. There are two sets of deflecting coils: horizontal and vertical. (In the illustration, only one set of coils is shown for simplicity.) The intensity of the beam can be varied. The electron beam produces a tiny, bright visible spot when it strikes the phosphor-coated screen.
To produce an image on the screen, complex signals are applied to the deflecting coils, and also to the apparatus that controls the intensity of the electron beam. This causes the spot to race across the screen from right to left, and from top to bottom, in a sequence of horizontal lines called the raster. As viewed from the front of the CRT, the spot moves in a pattern similar to the way your eyes move when you read a single-column page of text. But the scanning takes place at such a rapid rate that your eye sees a constant image over the entire screen.
The illustration shows only one electron gun. This is typical of a monochrome, or single-color, CRT. However, virtually all CRTs today render color images. These devices have three electron guns, one for the primary color red, one for the primary color green, and one for the primary color blue. The CRT thus produces three overlapping images: one in red (R), one in green (G), and one in blue (B). This is the so-called RGB colormodel.
In computer systems, there are several Display modes, or sets of specifications according to which the CRT operates. The most common specification for CRT displays is known as SVGA (Super Video Graphics Array). Notebook computers typically use liquid crystal display The technology for these displays is much different than that for CRTs.
Colour CRT
Raster Graphic And Vector Graphic
Raster Graphic
Most images you see on your computer screen are raster graphics. Pictures found on the Web and photos you import from your digital camera are raster graphics. They are made up of grid of pixels, commonly referred to as a bitmap. The larger the image, the more disk space the image file will take up. For example, a 640 x 480 image requires information to be stored for 307,200 pixels, while a 3072 x 2048 image (from a 6.3 Megapixel digital camera) needs to store information for a whopping 6,291,456 pixels.
Since raster graphics need to store so much information, large bitmaps require large file sizes. Fortunately, there are several image compression algorithms that have been developed to help reduce these file sizes. JPEG and GIF are the most common compressed image formats on the Web, but several other types of image compression are available.
Raster graphics can typically be scaled down with no loss of quality, but enlarging a bitmap image causes it to look blocky and "pixelated." For this reason, Vector Graphics are often used for certain images, such as company logos, which need to be scaled to different sizes.
File extensions: .BMP, .TIF, .GIF, JPG
Vector Graphic
Unlike JPEGs, GIFs, and BMP images, vector graphics are not made up of a grid of pixels. Instead, vector graphics are comprised of paths, which are defined by a start and end point, along with other points, curves, and angles along the way. A path can be a line, a square, a triangle, or a curvy shape. These paths can be used to create simple drawings or complex diagrams. Paths are even used to define the characters of specific typefaces.
Because vector-based images are not made up of a specific number of dots, they can be scaled to a larger size and not lose any image quality. If you blow up a raster graphic, it will look blocky, or "pixelated." When you blow up a vector graphic, the edges of each object within the graphic stay smooth and clean. This makes vector graphics ideal for logos, which can be small enough to appear on a business card, but can also be scaled to fill a billboard. Common types of vector graphics include Adobe Illustrator, Macromedia Freehand, and EPS files. Many Flash animations also use vector graphics, since they scale better and typically take up less space than bitmap images.
File extensions: .AI, .EPS, .SVG, .DRW
15) Video Display device
Ans:-A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers. The first computer monitors used Cathode ray tubes (CRTs), which was the dominant technology until they were replaced by LCD monitors in the 21st Century.
Referesh CRT
A cathode ray tube (CRT) is a specialized vacuumtube in which images are produced when an electron beam strikes a phosphorescent surface. Most desktop computer displays make useof CRTs.
The CRT in a computer display is similar to the"picture tube" in a television receiver. A cathode ray tube consists of several basic components, as illustrated below. The electron gun generates an arrow beam of electrons. The a nodes accelerate the electrons. Deflecting coils produce an extremely low frequency electro-magnetic field that allows for constant adjustment of the direction of the electron beam. There are two sets of deflecting coils: horizontal and vertical. (In the illustration, only one set of coils is shown for simplicity.) The intensity of the beam can be varied. The electron beam produces a tiny, bright visible spot when it strikes the phosphor-coated screen.
To produce an image on the screen, complex signals are applied to the deflecting coils, and also to the apparatus that controls the intensity of the electron beam. This causes the spot to race across the screen from right to left, and from top to bottom, in a sequence of horizontal lines called the raster. As viewed from the front of the CRT, the spot moves in a pattern similar to the way your eyes move when you read a single-column page of text. But the scanning takes place at such a rapid rate that your eye sees a constant image over the entire screen.
The illustration shows only one electron gun. This is typical of a monochrome, or single-color, CRT. However, virtually all CRTs today render color images. These devices have three electron guns, one for the primary color red, one for the primary color green, and one for the primary color blue. The CRT thus produces three overlapping images: one in red (R), one in green (G), and one in blue (B). This is the so-called RGB colormodel.
In computer systems, there are several Display modes, or sets of specifications according to which the CRT operates. The most common specification for CRT displays is known as SVGA (Super Video Graphics Array). Notebook computers typically use liquid crystal display The technology for these displays is much different than that for CRTs.
Colour CRT
A color CRT monitor displays color picture by using a combination of phosphors that emit different colored light.
By combining the emitted light a range of colors can be generated.
Two basic methods for producing color displays are:
1) Beam Penetration Method
Random scan monitors use the beam penetration method for displaying color picture.
In this, the inside of CRT screen is coated two layers of phosphor namely red and green.
A beam of slow electrons excites only the outer red layer, while a beam of fast electrons penetrates red layer and excites the inner green layer.
At intermediate beam speeds, combinations of red and green light are emitted to show two additional colors- orange and yellow.
Advantages
Less expensive
Disadvantages
Quality of images are not good as comparatable with other methods
Four colors are allowed only
2) Shadow Mask Method
Raster scan system are use shadow mask methods to produce a much more range of colors than beam penetration method.
In this, CRT has three phosphor color dots.
One phosphor dot emits a red light, second emits a green light and third emits a blue light.
This type of CRT has three electrons guns and a shadow mask grid as shown in figure below:
In this figure, three electrons beams are deflected and focused as a group onto the shadow mask which contains a series of holes.
When three beams pass through a hole in shadow mask they activate dot triangle as shown in figure below:
The colors we can see depend on the amount of excitation of red, green and blue phosphor.
A white area is a result of all three dots with equal intensity while yellow is produced with green and red dots and so on.
Advantages
Produce realistic images
Also produced different colors and shadows scenes.
Disadvantages
low resolution
expensive
electron beam directed to whole screen
Full Color System
Color CRTs in graphics systems are designed as RGB monitors. These monitors use shadow mask method and take the intensity level for each gun. A RGB color system with 34 bits of storage per pixel is known as full color system or true color system.
Full Color System
Color CRTs in graphics systems are designed as RGB monitors. These monitors use shadow mask method and take the intensity level for each gun. A RGB color system with 34 bits of storage per pixel is known as full color system or true color system.
Difference between Beam Penetration and Shadow Mask method.
Full Color System
Color CRTs in graphics systems are designed as RGB monitors. These monitors use shadow mask method and take the intensity level for each gun. A RGB color system with 34 bits of storage per pixel is known as full color system or true color system.
Difference between Beam Penetration and Shadow Mask method.
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