CH4 Rasterization & Raster Graphics

Question 1

What are raster graphics?

Answer 1

Images created by a grid of individual pixels, each with its own color value.

Question 2

Name common file formats for raster graphics.

Answer 2

• BMP
• JPEG
• PNG
• GIF
• TIFF

Question 3

What is a key characteristic of raster graphics?

Answer 3

Fixed resolution; scaling can lead to loss of quality (pixelation).

Question 4

Define a pixel.

Answer 4

The smallest individual element of an image displayed on a screen, representing a single point of color.

Question 5

How is the resolution of a raster image defined?

Answer 5

By its width (in pixels) and height (in pixels).

Question 6

What is rasterization?

Answer 6

The process of converting geometric shapes into a raster image made up of pixels.

Question 7

What is the first stage in the rasterization process?

Answer 7

Vertex Processing.

Question 8

What happens during primitive assembly in rasterization?

Answer 8

Vertices are assembled into primitives (triangles, lines, etc.) required for rendering.

Question 9

What is the role of the framebuffer in rasterization?

Answer 9

It stores the final colors, which hold pixel values ready for display on the screen.

Question 10

What does Bresenham’s Line Algorithm do?

Answer 10

Efficiently determines pixel positions for drawing straight lines based on their endpoints.

Question 11

What is the Midpoint Circle Algorithm used for?

Answer 11

Efficiently calculates pixel locations for rasterizing circles by leveraging symmetry.

Question 12

What is Z-buffering?

Answer 12

A depth-sorting method that manages depth information for pixels to ensure correct object display.

Question 13

List advantages of raster graphics.

Answer 13

• Capability to represent complex images with fine detail.
• Flexibility in editing pixel data.
• Wide compatibility with software for image manipulation.

Question 14

List disadvantages of raster graphics.

Answer 14

• Resampling quality loss when scaling.
• Larger file sizes than vector graphics.
• Memory-intensive when using high-resolution images.

Question 15

What are common applications of raster graphics?

Answer 15

• Digital Photography
• Graphic Design
• Web Graphics
• Video Games

Question 16

How do raster graphics differ from vector graphics?

Answer 16

Raster graphics are composed of pixels, while vector graphics are composed of mathematical paths and shapes.

Question 17

What is a key conclusion about rasterization?

Answer 17

It is a fundamental process that enables the rendering of complex images in computer graphics.

Question 18

What is the first step in rasterizing a triangle?

Answer 18

Define the Triangle’s Vertices.

Question 19

What does the scanline fill algorithm do?

Answer 19

Determines which pixels lie inside the triangle boundaries for filling.

Question 20

Fill in the blank: Rasterization is the process that converts the geometric representation of shapes into a grid of _______.

Answer 20

[pixels]

Question 21

True or False: Raster graphics maintain quality when scaled.

Answer 21

False

Question 22

What is the purpose of the Scanline Polygon Fill Algorithm?

Answer 22

To fill a polygon with color by determining intersections on horizontal scanlines.

Question 23

What does the term ‘fragment processing’ refer to?

Answer 23

Processing fragments generated from rasterization to apply effects like shading and texturing.

Question 24

What is the main benefit of using raster graphics in digital photography?

Answer 24

Ability to capture, edit, and display detailed images.

Question 25

After rasterizing a triangle, how can its interior be filled?

Answer 25

Using techniques like the scanline fill algorithm.

Question 26

What is the significance of understanding raster graphics for professionals?

Answer 26

Crucial for fields such as graphic design, animation, and software development.

Question 27

What is the first step to fill a polygon with color in raster graphics?

Answer 27

Identify the edges of the polygon.

Question 28

How do you determine where a polygon intersects with horizontal scanlines?

Answer 28

For each horizontal scanline, determine where the polygon intersects.

Question 29

What are the start and end points used for in filling a polygon?

Answer 29

Identify the start and end points of each intersection to fill in the pixels between those points.

Question 30

What is an example of texture mapping in raster graphics?

Answer 30

Applying a 2D texture, like a brick pattern, onto a 3D surface.

Question 31

What are UV coordinates used for in texture mapping?

Answer 31

To define how the texture corresponds to the object's surface.

Question 32

What visual comparison is made in the demonstration of texture mapping?

Answer 32

Display the original texture and the 3D object with the applied texture side-by-side.

Question 33

What does color depth refer to in raster graphics?

Answer 33

The number of bits used to represent the color of a single pixel.

Question 34

What is illustrated by displaying images with varying color depths?

Answer 34

How color depth affects image quality.

Question 35

What activity can students do to explore the effects of color depth?

Answer 35

Explore how the change in depth influences the amount of detail that can be represented.

Question 36

What is a discussion topic regarding color depth and image quality?

Answer 36

The impact of color depth on file size and quality.

Question 37

What compression technique is mentioned that affects image quality?

Answer 37

JPEG compression.

Question 38

What is the purpose of implementing anti-aliasing techniques?

Answer 38

To smooth edges of raster graphics.

Question 39

What is an example of an anti-aliasing technique?

Answer 39

Supersampling or smoothing.

Question 40

What is used to show the effect of anti-aliasing visually?

Answer 40

Present two images of the same object, one with anti-aliasing applied and one without.

Question 41

What are some real-world applications of raster graphics?

Answer 41

* Digital photography * Gaming * Web design

Question 42

What hands-on activity can students do related to raster graphics?

Answer 42

Import raster images into graphics editing software and apply various techniques.