] Astrophysics Pyramid Image Processing (APIP) is a set of
] multiresolution image processing routines and statistical
] descriptors developed by Dr. Charles H. Anderson at the
] Washington University Medical School in collaboration
] with Dr. William D. Langer at the Jet Propulsion
] Laboratory, California Institute of Technology.
]
] APIP is different from most other multiresolution
] software packages in its emphasis on overcomplete
] non-orthogonal representations. While most scientists are
] more familiar with the orthonormal wavelets, their
] strength is in data compression and not in image
] analysis. Orthonormal wavelets provide critically sampled
] representations with minimal storage, but the constraint
] of orthogonality leads to filter designs that are not
] necessarily the best for image analysis (cf. Strang 1989,
] Simoncelli et al. 1992).

Astrophysics Pyramid Image Processing (APIP)

The goal with this worksheet is to deepen the understanding of the gradient and to illustrate how the gradient can be used for image processing. Finally, you will have the opportunity to play around with a mathematical program for doing edge detection which is based upon the ideas illustrated in this lab.

Me: Great source on gradient vectors and image processing... explained to me what the upside down triangle meant ;)

Visualizing calculus: The use of the gradient in image processing

The Laplace Operator
We give one more example of why (linear) digital filtering, implemented via the FTT may be of interest.

The Laplace Operator

] Below is a quick-reference table of the notation we
] recommend for the content whose correct notation is often
] found written with various variables and symbols. Click
] on any of the content names to be taking to a brief
] discussion of it and example code of how to mark-up the
] MathML correctly.

Nice DSP notation reference.

DSP notation

] The .bmp file format (sometimes also saved as .dib) is
] the standard for a Windows 3.0 or later DIB(device
] independent bitmap) file. It may use compression (though
] I never came across a compressed .bmp-file) and is (by
] itself) not capable of storing animation. However, you
] can animate a bitmap using different methods but you have
] to write the code which performs the animation. There are
] different ways to compress a .bmp-file, but I won't
] explain them here because they are so rarely used. The
] image data itself can either contain pointers to entries
] in a color table or literal RGB values (this is explained
] later).

The .bmp file format

Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer. It is used by MPEG playback software, emulators, and many popular games, including the award winning Linux port of "Civilization: Call To Power."

Simple DirectMedia Layer supports Linux, Windows, BeOS, MacOS Classic, MacOS X, FreeBSD, OpenBSD, BSD/OS, Solaris, IRIX, and QNX. There is also code, but no official support, for Windows CE, AmigaOS, Dreamcast, Atari, NetBSD, AIX, OSF/Tru64, RISC OS, and SymbianOS.

SDL is written in C, but works with C++ natively, and has bindings to several other languages, including Ada, Eiffel, Java, Lua, ML, Perl, PHP, Pike, Python, and Ruby.

Simple DirectMedia Layer

The lessons on this page may contain mistakes, poor commenting, and should not be considered the best resource to learn OpenGL from. What you do with the code is up to you. I am merely trying to make the learning process a little easier for those people new to OpenGL. If you are serious about learning OpenGL, you should spend the money and invest in the OpenGL Red Book (ISBN 0-201-46138-2) and OpenGL Blue Book (ISBN 0-201-46140-4). I have the second edition of each book, and although they can be difficult for the new OpenGL programmer to understand, they are by far the best books written on the subject of OpenGL. Another book I would recommend is the OpenGL Superbible, although opinions vary. It is also important that you have a solid understanding of the language you plan to use. Although I do comment the non-GL lines, I am self-taught, and may not always write proper or even good code. It's up to you to take what you have learned from this site and apply it to projects of your own. Play around with the code, read books, ask me questions if need be. Once you have surpassed the code on this site or even before, check out some of the more professional sites such as OpenGL.org. Also be sure to visit the many OpenGL links on my page. Each site I link to is an incredible asset to the OpenGL community. Most of these sites are run by talented individuals that not only know their GL, they also program a lot better than I do. Please keep all of this in mind while browsing my site. I hope you enjoy what I have to offer!

Neon Helium OpenGL Tutorials -- Examples for every imaginable language and platform

Abstract—We describe a technique for image encoding in which local operators of many scales but identical shape serve as the basis functions. The representation differs from established techniques in that the code elements are localized in spatial frequency as well as in space.

The Laplacian Pyramid as a Compact Image Code -- Classic Paper

] Document Image Analysis is concerned with the problem of
] transferring the document images into electronic form.
] This would involve the automatic interpretation of images
] of printed and handwritten documents, including text,
] forms, postal envelopes, bank cheques, engineering
] drawings, maps etc [1]. Several systems which work in
] specific domains, like the ones mentioned above, have
] been developed. Document Image Analysis can be defined as
] the process that performs the overall interpretation of
] document images [2]. It is a key area of research for
] various applications in machine vision and media
] processing, including page readers, content-based
] document retrieval, and digital libraries. The first step
] of a Document Image Analysis system would be to extract
] the text, figures, tables, graphs, charts, mathematical
] equations, etc, from the background. This would involve
] segmentation of the document image into equations,
] tables, charts and text. An important follow up problem
] in multi-lingual documents is the segmentation of text
] based on the scripts. This project aims to separate out
] the regions of different scripts in the scanned image of
] a document. Such a system would be essential in a
] multilingual country like India, where a single document
] (example. passport application form, public examination
] question paper, railway booking form etc) page may
] contain words in two or more language scripts, typically
] English, Hindi and the local language.%

Good explanation of Gaussian/Luplasian pyramids.

Introduction to Guassian/Luplasian Pyramids

PSCP (yes, there IS a patent application) is not simple encryption. It goes much further. "Encryption works by leveraging millions of possibilities," says Paul Tyma, chief scientist (I suspect the ONLY scientist) at PreEmptive. "To decrypt a message you only need one key, but there are millions or billions of possible keys to choose from. That's a challenge, sure, but once you get the key, you are in and in forever. PSCP is vastly more complex. When a computer program runs, the computer can follow millions of paths to get the job done. We leverage those millions of paths and transform them into billions of paths instead. We no longer let a hacker reverse-engineer a program on paper, we force them to reverse-engineer as the program runs. Every time a piece (of code) runs, it can be different. You can't just examine program parts, you have to watch everything at once. It is orders of magnitude more difficult to reverse-engineer. And the increase in processing overhead is trivial. PSCP, if done right, costs almost nothing."

Misinterpretation PBS | I, Cringely . Archived Column