Introduction to Video and Image Processing

Tracking (Introduction to Video and Image Processing) Part 1

One of the central questions in video processing is how to follow an object over time. Imagine you are designing a game where the position of the hand is used as a controller. What you need from your video processing software is then the position of the hand in each image and hence a temporal […]

Tracking (Introduction to Video and Image Processing) Part 2

Good Features to Track Instead of only focusing on the position when tracking objects we can also include the features we are using to classify the different objects. This basically means we are combining the matching problem describe above with the feature classification problem discussed in Chap. 7. In practice we base the matching on […]

Geometric Transformations (Introduction to Video and Image Processing) Part 1

Most people have tried to do a geometric transformation of an image when preparing a presentation or when manipulating an image. The two most well-known are perhaps rotation and scaling, but others exist. In this topic we will describe how such transformations operate and discuss the issues that need to be considered when doing such […]

Geometric Transformations (Introduction to Video and Image Processing) Part 2

Backward Mapping The solution is to avoid forward mapping and instead use backward mapping. Backward mapping maps from g(x’,y’) to f(x, y). That is, it goes through the output image, g(x’,y’), one pixel at a time (using two for-loops) and for each position (x’,y’) it uses the inverse transformation to calculate (x, y). That is, […]

Visual Effects (Introduction to Video and Image Processing) Part 1

In some situations the end goal of video and image processing is not to extract information, but rather to create some kind of visual effect. Or in other words, just for the fun of it. This can be done in many different ways, where some are more interesting than others. In this topic we present […]

Visual Effects (Introduction to Video and Image Processing) Part 2

Twirl Transformation Geometric transformations can easily become so complicated that the backward mapping is very hard or even impossible to derive. Such transformations are therefore often defined directly in the output domain, meaning that the forward mapping is not defined but only the backward mapping. The next three transformations are of this type. The first […]

Application Example: Edutainment Game (Introduction to Video and Image Processing)

It was late Friday night in a local bar downtown in IP-valley. Mick and SB were hanging out and debating who had the most miserable life. At one point the bartender interrupted them and basically told them to shut the fuck up or leave the bar. “Too depressing,” he said. Mick looked at him with […]

Application Example: Coin Sorting Using a Robot (Introduction to Video and Image Processing)

Mick and SB were talking quietly in their local bar when the bartender’s nephew, Fred, approached them. “I just inherited a robot,” he said out of the blue. “Well, of course you have, terminator or R2D2?” Mick said while laughing. “You inherited a what?” SB tried a bit more polite. “A robot.” “What do you […]

Bits, Bytes and Binary Numbers (Introduction to Video and Image Processing)

When working with images it is useful to know something about how data are stored in the memory of the computer. Most values associated with images are closely related to the internal representation of the numbers. The value of one pixel is often stored as one byte for example. The memory of the computer can […]

Mathematical Definitions (Introduction to Video and Image Processing) Part 1

This topic provides some basic mathematical definitions. The topic is intended for readers who do not have a mathematical background or readers who need a “brush-up”. Absolute Value The absolute value of a number, z, is written as Abs(z) or |z|. It is calculated by deleting the “minus” in front of the number. This means […]

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