Computer Graphics ( For BTech, BCA, MCA & UGC-NET Exams)

Discover the pixel, the smallest unit of a digital image, and how per-pixel colors build onscreen objects; higher pixel density enhances resolution and sharpness on displays.

Explore how screen resolution maps pixels across width and height to determine image clarity and sharpness. Learn how common resolutions like 720p, 1080p, and 4K relate to display quality.

Explain the aspect ratio as the width-to-height relation and highlight common standards like 4:3, 16:9, and 21:9. Show how software templates preserve image and video proportions across different screen sizes.

Explore the concepts of dpi and ppi, defining how many dots or pixels fit in an inch on screens and printers, and how pixel density improves resolution and image clarity.

Examine how frames define a rectangular region for placing graphics and text, and how a frame buffer stores image data to enable animation through sequences of frames.

Explore how saturation, or chroma, controls the depth and intensity of colors in images, making them more colorful and vibrant by increasing color depth and brightness.

Define contrast as the difference between darkest and brightest image areas, identify high versus low contrast, and explain its effect on clarity, visibility, lighting, and camera quality.

Rasterization converts vector image descriptions into pixels for display on the screen. It reads the frame data stored as bits and transforms picture definitions into the final output.

Explain how the aliasing effect creates jagged lines on low-resolution graphics displays and demonstrate smoothing by adjusting the intensity of the pixels along the line and dead pixels.

Foreshortening teaches how to depict a 3d scene in a 2d image by projecting objects with distance, so farther parts appear smaller and proportions adjust for realism.

Explore the overstrike effect in computer graphics by showing how writing the same pixel repeatedly intensifies its color, and how multiple hits alter pixel intensity in photographic media.

Explore flickering as a pixel glitch caused by a too-low refresh rate, where slow display of pixels creates flashing on screens; higher refresh rates reduce this effect.

In halftoning, a reprogramming technique uses dots of varying size and spacing to simulate continuous tone, producing brighter or dimmer areas and a range of visual effects.

Explore dithering, a graphic technique that fools the eye into seeing more colors. Learn how dot spacing creates perceived gray shades from limited palettes and helps manage color banding.

learn how a plotter, a vector graphics printing device, draws continuous lines point to point with a pen, enabling better graphics than dot-based printing, and introduces display devices.

Explore display devices as the main output for videos, images, and text, covering crt, lcd, and electro-luminescent plasma types and the electron-beam phosphor emission mechanism.

Explore how color crt monitors use an electron gun, focusing and deflection, and a shadow mask to combine red, green, and blue phosphor for a displayed image.

Explore raster scan displays that draw images line by line from top left to bottom right with refresh. Compare interlaced and noninterlaced schemes, color depth, and memory for pixel data.

Demonstrates random scan display by drawing image outlines as randomly placed lines using XY coordinates, refreshed 30–60 Hz from memory that stores line-based picture definitions.

Compare raster scan display and random scan display, noting that raster uses line-by-line filling with lower resolution and scattered pixels, while random scan draws smooth edges with higher resolution and more colors.

Explore the direct view storage tube display, a 2-d storage device using electron beams to write images on a storage grid for a lasting screen image.

Explain how plasma displays use noble gas plasma cells coated with phosphor to form color pixels, with glass plates and magnesium oxide protective layer, and discuss brightness and contrast tradeoffs.

Learn how LCD displays use red, green, and blue LEDs to form images with RGB pixels, and how pixel spacing and PCB-mounted LEDs determine resolution and energy efficiency.

Explore the construction and operation of liquid crystal displays, including polarizers, backlight, and the twisted-nematic effect, and compare active and passive matrix LCDs.

Explore conventional and organic light emitting diode displays, their layer structure—electron transport layer, organic emitters, injectors, anode, glass substrate—and how voltage drives recombination to emit light across colors.

Explore how display processors and the video controller convert frame buffer data into screen pixels, using scan conversion and RGB values at X and Y coordinates to render images.

Explore input devices that let users interact with a computer by sending data such as text, graphics, or audio, including keyboards, mice, scanners, touchpads, microphones, and touchscreens.

Introduce the coordinate system to locate points, show a point at (3,3) from the origin, and outline two-dimensional frames such as modeling, world, and device coordinates.

Explore coordinate systems in computer graphics, including object (modeling) coordinates, world coordinates, and device coordinates, with right- and left-handed systems and homogeneous coordinates for 2D projection.

Explore graphics software from general programming packages to special purpose applications that enable 2D and 3D design and image manipulation, including AutoCAD and Adobe tools for architecture and engineering.

Graphics standards define specifications and a common interface between computer systems and subsystems, enabling portable graphics across hardware through APIs and libraries that standardize coordinate-based primitives like lines and endpoints.

Explore graphics output primitives by examining line drawing and circle generating algorithms, including the Midpoint circle generating algorithm, comparing merits and demerits, and implementing them in C.

learn how to draw a line on screen with the digital differential analyzer, calculating dx, dy, steps, and slope via y = mx + c, with pixel rounding.

Explore Bresenham's line drawing algorithm, including the decision parameter, slope handling, and pixel selection to draw lines efficiently without floating point arithmetic.

Apply the beauty method to determine missing values in a numerical problem, using rounding rules and incremental steps to fill gaps and arrive at final values.

Code the DDA line algorithm in C++ with a graphics library, computing increments and plotting pixels to draw a line between two coordinates on screen.

Code Bresenham's line in a graphics program by initializing graphics and reading start and end coordinates. Draw the line using a decision parameter for slopes under 45 degrees.

Explore the midpoint circle generating algorithm, using radius, symmetry, and a decision parameter to plot circle points across octants by reflecting coordinates.

Explore Bresenham's circle generating algorithm using a midpoint decision parameter to plot circle points across octants by symmetry around the origin using the circle radius.

Plot circle pixels at 170 degrees from the x axis in the anti-clockwise direction using the platinum algorithm with five-degree gaps, then reflect coordinates to other quadrants.

Implement the midpoint circle algorithm to draw a circle by plotting pixels around a center, initialize graphics, use a decision parameter, and treat the center as the origin.

Master Bresenham's circle algorithm in C to generate a circle by plotting symmetric pixels from a center with a given radius and a decision parameter.

Explore geometric transformations, implementing 2D and 3D transformations in C, including translation, scaling, rotation, and reflection. See how object position, size, and orientation change through these techniques.

Explore 2d translation: shift an object by a translation vector to new x and y coordinates, with practical examples.

Apply 2d rotation using rotation matrices to rotate points and polygon vertices, comparing anticlockwise and clockwise transformations, with origin placement and coordinate updates.

Explain 2d scaling in computer graphics by applying a scaling factor to coordinates, yielding new coordinates x' = s x and y' = s y, as in (0,3) to (0,9).

Perform two dimensional reflection by flipping coordinates across the x-axis or y-axis, using the matrices for x-axis [1 0; 0 -1] and y-axis [-1 0; 0 1] to obtain new coordinates.

Explore 2d shearing in computer graphics by transforming object coordinates along the x and y axes using shear matrices, revealing how directional shear changes shape and coordinates.

Discover how homogeneous coordinates represent two-dimensional and three-dimensional points with an extra w component, enabling translation, rotation, and scaling via matrices and handling points at infinity.

Explore composite matrix transformation by chaining translation, reflection, and rotation to form a single matrix, highlighting order of operations and homogeneous coordinates.

Explore reflecting a two-dimensional polygon about the line y = 2 by translating to the origin, reflecting across the x-axis, and translating back using a composite matrix.

Magnify a two-dimensional object by a factor of two while keeping point C (5,2) fixed, using translate-scale-translate with homogeneous 3×3 matrices and a composite transformation.

Build a composite transformation matrix to reflect about any line with slope m and intercept b by translating, rotating, reflecting, and reversing the steps in correct matrix order.

Explains 3D translation using homogeneous coordinates and four-by-four translation matrices, and demonstrates shifting a point along x, y, and z with a practical example.

Explore 3d rotation by rotating points along the x, y, and z axes using homogeneous rotation matrices, with clockwise and anticlockwise conventions and practical 90-degree examples.

Apply 3d scaling along the x, y, and z axes using a diagonal scaling matrix; increase size with factors greater than one and decrease with factors less than one.

Explore 3d reflection by applying reflections on xy, xz, and yz planes. Use reflection matrices to transform coordinates and observe negative components.

Explore 3d shearing transformations in computer graphics, applying matrix-based shearing along x, y, and z axes to deform object shape while preserving volume and overall position.

solve a 3d transformation problem by translating a shape to origin, aligning a 45-degree rotation axis, applying composite rotation matrices, and undoing transforms to obtain rotated coordinates.

Compute a rotation about an arbitrary 3-D axis by translating to origin, aligning with a primary axis, applying the rotation, and reversing transforms with the composite matrix using direction cosines.

Inspect how two-dimensional viewing maps a world window to a device viewport through projection, scaling, and coordinate transformation, preserving aspect while fitting images on diverse displays.

Learn to map world coordinates to a viewport, then to device coordinates using normalization, scaling, and viewport transformations to render images on display.

Explains the two-dimensional viewing pipeline by mapping window coordinates to viewport, applying projection, clipping, normalization, and device coordinates to render a world view.

The lecture explains the two-stage transformation from a world window to a viewport and then to a workstation window, using normalization matrices and min and max coordinates.

Compute the normalized transformation matrix to map the rotated window to the normalized device screen, using translate, rotate, and translate back in a composite matrix, with window and viewport extents.