用cg的00_02_imaging.pptx

Recap so far

What is an image?

  1. Sampling and aliasing
  2. Thinking in frequency
  3. image filtering

1 Introduction

1.1 Color is important

  1. To start us off, let’s look at these four colorful images. Can You Believe This is a Single Photograph?
  2. what can you tell me about the differences between these images?
  3. Major trick. The scene was arranged by looking through the viewfinder of the camera, which, as like the image, offers a fixed perspective which makes this possible.

Untitled

http://youtube.com/watch?v=oJGN6sX5Ekg

misconception⇒Color is important

1.2 What is color?

1.2.1 grayscale & color image

1.2.1 Raster images

Color is so much more than just three channels.

Especially for human vision, color is important.

1.2.2 受控的幻觉：对颜色的感知是“环境”依赖的

Untitled

在有些人看来，这是一条白色额和黄色相间的裙子；在另一些人看来，这裙子明明是蓝色和黑色相间。

这是一个非常奇特的例子，因为每个人只能看到自己看到的——比如在我看来，这就是白黄色，我无法想象为什么有人能看成蓝黑色。也许你眼中这就是蓝黑色，也许你需要多问几个朋友才能体会到这个悖论。你会发现人们坚定地分成了两派。

我在一天早晨，不时的在两派间切换。

这是怎么回事呢？赛斯在一个访谈中 [2] 是这么解释的：关键在于，你默认这张照片是在室内还是户外拍摄的。