This is a continuation of my blog post on intro to digital watermarking. In that post, we discussed what digital watermarking is and how it can be achieved. Here, we will discuss the intuition behind image watermarking and a few techniques that can be used. If you look at enough number of images, you will … Continue reading The Intuition Behind Image Watermarking
Category: Image Processing
Digital Watermarking
Let's say you want to verify the authenticity of a signal. The signal can take any form like an image, audio, video, or any other kind of bit stream. By now, everybody would have heard the term "watermark" being used in the general sense. The most common example would be currency notes. Watermarks are embedded … Continue reading Digital Watermarking
Image Steganography
As discussed in my previous post, steganography is the art of hiding the fact that communication is taking place. We achieve this by hiding original information inside other information known as carrier files. Many different carrier file formats can be used, but digital images are the most popular because of their frequency of occurrence on … Continue reading Image Steganography
What Are Conditional Random Fields?
This is a continuation of my previous blog post. In that post, we discussed about why we need conditional random fields in the first place. We have graphical models in machine learning that are widely used to solve many different problems. But Conditional Random Fields (CRFs) address a critical problem faced by these graphical models. … Continue reading What Are Conditional Random Fields?
Why Do We Need Conditional Random Fields?
This is a two-part discussion. In this blog post, we will discuss the need for conditional random fields. In the next one, we will discuss what exactly they are and how do we use them. The task of assigning labels to a set of observation sequences arises in many fields, including computer vision, bioinformatics, computational … Continue reading Why Do We Need Conditional Random Fields?
Derandomization Of RANSAC
Let's say you are a clothes designer and you want to design a pair of jeans. Since you are new to all this, you go out and collect a bunch of measurements from people to see how to design your jeans as far as sizing is concerned. One aspect of this project would be to … Continue reading Derandomization Of RANSAC
The Ramifications Of H.265
The International Telecommunication Union (ITU) recently approved the next generation video format known as H.265, which would be the successor to the current H.264 standard. H.265, also informally known as High Efficiency Video Coding (HEVC), is supposed to be twice as efficient as H.264 in terms of compression. H.265 relies on the fact that processing … Continue reading The Ramifications Of H.265
Curvelet Analysis
This blog post is a continuation of my previous post on ridgelet analysis. Motivated by the problem of finding efficient representation of objects, people introduced yet another representation system called the curvelet transform. This is very efficient in representing objects that have discontinuities along curves, and compressing image data as well. Curvelets are a non-adaptive technique … Continue reading Curvelet Analysis
Ridgelet Analysis
The pioneering work of researchers on signal processing paved the way to the powerful concept of multiresolution analysis. This is perhaps best known under the generic name of wavelets. Signals occur in the form of images, voice, radar, sonar, infrared etc. Different techniques have been developed over the years to understand these signals. Multiresolution provides … Continue reading Ridgelet Analysis
Principal Component Analysis
Principal Component Analysis (PCA) is one of most useful tools in the field of pattern recognition. Let's say you are making a list of people and collecting information about their physical attributes. Some of the more common attributes include height, weight, chest, waist and biceps. If you store 5 attributes per person, it is equivalent … Continue reading Principal Component Analysis
Perpetual Enigma 