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1.10.2 Raster Scan Displays

Raster scan displays represent images as a matrix of pixels organized in rows and columns. The display hardware refreshes the
screen sequentially, scanning from the top-left corner to the bottom-right corner. Each pixel is assigned a color value stored in the
frame buffer.

Raster displays are the most common display technology used in modern computer graphics systems due to their ability to represent
complex images, including filled polygons, textures, and shading effects. Scan conversion algorithms are used to determine which
pixels should be activated for rendering geometric primitives such as lines, circles, and polygons.

1.10.3 LCD and Modern Display Devices

Liquid Crystal Displays (LCDs) and other modern display devices such as LED and OLED screens are based on raster scan principles
but provide higher resolution, improved color accuracy, and lower power consumption. These devices use arrays of tiny cells to
control light intensity and color at each pixel.

Modern displays support advanced features such as high refresh rates and high dynamic range (HDR), which significantly enhance
the realism and clarity of computer-generated images. As display technology continues to evolve, efficient scan conversion and
rendering techniques remain essential for achieving high-quality visual output.

SUMMARY AND NOTES
In this chapter, we have set the stage for our top-down development of computer graphics.We presented the overall picture so that
you can proceed to writing graphics application programs in the next chapter without feeling that you are working in a vacuum. We
have stressed that computer graphics is a method of image formation that should be related to classical methods of image
formation—in particular, to image formation in optical systems, such as in cameras. In addition to explaining the pinhole camera,
we have introduced the human visual system; both are examples of imaging systems. We described multiple image-formation
paradigms, each of which has applicability in computer graphics. The synthetic-camera model has two important consequences for
computer graphics. First, it stresses the independence of the objects and the viewer—a distinction that leads to a good way of
organizing the functions that will be in a graphics library. Second, it leads to the notion of a pipeline architecture, in which each of
the various stages in the pipeline performs distinct operations on geometric entities and then passes on the transformed objects to
the next stage. We also introduced the idea of tracing rays of light to obtain an image. This paradigmis especially useful in
understanding the interaction between light and materials that is essential to physical image formation. Because ray tracing and
other physically based strategies cannot render scenes in real time, we defer further discussion of them until Chapter 11. The
modeling–rendering paradigm is becoming increasingly important. A standard graphics workstation can generate millions of line
segments or polygons per second at a resolution exceeding 2048 × 1546 pixels. Such a workstation can shade the polygons using a
simple shading model and can display only visible surfaces at this rate. However, realistic images may require a resolution of up to
4000 × 6000 pixels to match the resolution of film and may use light and material effects that cannot be implemented in real time.
Even as the power of available hardware and software continues to grow, modeling and rendering have such different goals that
we can expect the distinction between a modeling and a rendering to survive. Our next step will be to explore the application side
of graphics programming. We use the OpenGL API, which is powerful, is supported on most platforms, and has a distinct architecture
that will allow us to use it to understand how computer graphics works, from an application program to a final image on a display.