2. CARA MUDAH MENGHITUNG MEMORI PENYIMPANAN CITRA/GAMBAR

Summary

In this educational session, the instructor explores the fundamental concepts of digital image processing. The discussion covers topics such as digital image representation, the differences between continuous and discrete images, and the process of digitalization, including spatial sampling and intensity quantization. Key elements of digital images, such as color, brightness, contrast, and pixel coordinates, are explained, along with the importance of resolution and file formats. The session also touches on memory requirements for storing digital images and includes practical exercises and examples to enhance understanding of digital image systems.

Takeaways

• 😀 The lesson covers the basics of digital images and image recording systems, including the concept of digital images and the process of image digitization.
• 😀 Two main types of images are discussed: continuous (analog) and discrete (digital) images, with digital images being created through digitization of continuous images.
• 😀 Digital images are formed by a collection of pixels, and the conversion of continuous images to digital images is done through spatial sampling and intensity quantization.
• 😀 Spatial sampling (or sampling) involves representing a region in a continuous image within a grid, while intensity quantization involves grouping grayscale values into discrete levels.
• 😀 The number of possible colors in a digital image is determined by the bit depth. For example, 2-bit images can have 4 possible color levels, and 8-bit images can have 256 color levels.
• 😀 The resolution of an image is crucial, and higher resolution means more pixels per unit of area, making the image appear smoother and more detailed.
• 😀 Key elements of a digital image include color, brightness (intensity of light), contrast (distribution of light and dark), and color saturation (intensity of color).
• 😀 The coordinate system for digital images differs from Cartesian coordinates. In digital images, the origin is at the top-left corner, with pixel values increasing to the right and down.
• 😀 Image formats include binary, grayscale, true color, and indexed color, each representing different ways of storing color information.
• 😀 The storage and memory requirements of digital images are influenced by image size, bit depth, and resolution. For example, higher resolution and bit depth require more storage space.

Q & A

What are the two types of images based on the image acquisition system?

The two types of images based on the image acquisition system are continuous images (analog) and discrete images (digital).

What is the key difference between continuous images and discrete images?

Continuous images (analog) are formed by optical systems that receive analog signals with light intensity ranging from 0 to infinity. Discrete images (digital), on the other hand, are the result of the digitalization process of continuous images, where the light intensity is represented by discrete signals based on bit-depth.

What is image digitization, and how is it done?

Image digitization is the process of converting a continuous image into a discrete or numerical representation. It is done through spatial digitization (sampling) and intensity digitization (quantization).

What is spatial digitization (sampling)?

Spatial digitization (sampling) refers to the process of representing a specific region of a continuous image into a grid of square pixels. The image is divided into discrete points that correspond to specific coordinates.

How does the resolution of an image change with the number of pixels?

As the number of pixels increases in an image, its resolution becomes higher, making the image smoother and clearer. A larger number of pixels means more detail and a finer visual representation.

What is intensity digitization (quantization) in image processing?

Intensity digitization (quantization) is the process of grouping continuous grayscale values of an image into a certain number of levels or steps, based on the bit-depth. The more bits used, the greater the number of possible grayscale levels, resulting in a higher quality image.

What is the effect of using more bits for quantization?

Using more bits for quantization increases the number of possible grayscale levels, leading to better image quality because it can represent finer variations in light intensity.

How does the coordinate system differ between Cartesian coordinates and pixel coordinates in digital images?

In Cartesian coordinates, the origin (0,0) is at the bottom left, with the x-axis moving right and the y-axis moving up. In pixel coordinates for digital images, the origin is at the top-left corner, with the x-axis moving right and the y-axis moving down.

What are the different types of image formats based on storage and representation?

The different types of image formats based on storage and representation include binary images, grayscale images, true color images (RGB), and indexed color images.

What is the difference between bitmap and vector image formats?

Bitmap images are composed of a grid of pixels, each with specific colors and intensities. They are resolution-dependent. Vector images, on the other hand, are based on mathematical equations to represent shapes and are resolution-independent.