数字图像处理3rd - Chapter 1 - 3

 

1.3 Examples of Fields that Use Digital Image Processing

Today, there is almost no area of technical endeavor that is not impacted in some way by digital image processing. We can cover only a few of these applications in the context and space of the current discussion. However, limited as it is, the material presented in this section will leave no doubt in your mind regarding the breadth and importance of digital image processing. We show in this section numerous areas of application, each of which routinely utilizes the digital image processing techniques developed in the following chapters. Many of the images shown in this section are used later in one or more of the examples given in the book. All images shown are digital.

 

1.3 使用数字图像处理的实例

今天，几乎没有一个技术领域不受数字图像处理的影响。在当前讨论的背景和空间下，我们只能涵盖其中的一些应用。然而，尽管有限，本节介绍的资料将使你对数字图像处理的广度和重要性深信不疑。我们在本节中展示了许多应用领域，其中每一个领域都利用了以下各章中开发的数字图像处理技术。本节所展示的许多图像在后面的例子中都会用到。所有显示的图像都是数字的。

The areas of application of digital image processing are so varied that some form of organization is desirable in attempting to capture the breadth of this field. One of the simplest ways to develop a basic understanding of the extent of image processing applications is to categorize images according to their source (e.g., visual, X-ray, and so on). The principal energy source for images in use today is the electromagnetic energy spectrum. Other important sources of energy include acoustic, ultrasonic, and electronic (in the form of electron beams used in electron microscopy). Synthetic images, used for modeling and visualization, are generated by computer. In this section we discuss briefly how images are generated in these various categories and the areas in which they are applied. Methods for converting images into digital form are discussed in the next chapter.

数字图像处理的应用领域是如此之多，以至于在试图捕捉这个领域的广度时，需要好好组织一下。对图像处理的应用范围有一个最简单的了解，就是根据图像的来源（如视觉、X射线等）对其进行分类。今天使用的图像的主要能量来源是电磁能谱。其他重要的能量来源包括声学、超声波和电子（以电子显微镜中使用的电子束的形式）。用于建模和可视化的合成图像是由计算机生成的。在本节中，我们将简要讨论这些不同类别的图像是如何产生的，以及它们的应用领域。将图像转换为数字形式的方法将在下一章讨论。

Images based on radiation from the EM spectrum are the most familiar, especially images in the X-ray and visual bands of the spectrum. Electromagnetic waves can be conceptualized as propagating sinusoidal waves of varying wavelengths, or they can be thought of as a stream of massless particles, each traveling in a wavelike pattern and moving at the speed of light. Each massless particle contains a certain amount (or bundle) of energy. Each bundle of energy is called a photon. If spectral bands are grouped according to energy per photon, we obtain the spectrum shown in Fig. 1.5, ranging from gamma rays (highest energy) at one end to radio waves (lowest energy) at the other.