Image Manipulation Programs

Colour Swap: Executable or Text Version

This program just swaps the colours around in an image. It's useful as a basic illustration of the use of embedded Assembler, for those who download the TEXT version for use in BBC BASIC for Windows.

Greyscale:Either SIMPLE Executable or Text Version or FILTER OPTIONS Executable or Text Version.

This rewritten Assembly Language enhanced facility enables you to convert a jpg or bmp photo to black and white. The SIMPLE version has no user options, and automatically saves the result with the suffix-appended name of the original. The FILTER OPTIONS version enables choice of Standard, Red, Green, Blue, Yellow or New Standard filters.

Solariser: Executable or Text Version

Version operating on all .BMP file types, modified by Richard Russell: Executable or Text Version

This facility only works on 24-bit colour .BMP files. It emulates the effect of exposing a colour negative to light during the film development process. It can produce attractive, psychadelic looking effects.

It works essentially by reversing all the colours in a bitmap ABOVE a certain limit - so that relatively dark areas remain unchanged, but areas lighter than that certain limit get DARKER.

The second picture on the top page is an example of SOLARISER applied to a picture of a cloudy sky.

Glass: Executable or Text Version

A facility for producing a combined image formed by viewing a second image through a "stained glass" version of the first one chosen. The images must be of the same dimensions. The gradation is very smooth. The result can be saved as a 100% quality jpg file. Revised January 2018.

Reflections: Executable or Text Version

Using just the reflections routine from the foregoing Fractal Landscape program, you can take any .jpg file listed in your standard C:/Documents and Settings/Owner/My Documents/My Pictures/ file on your PC, and make a reflection of it. I have used it to make some Desktop Background pictures, such as the one below.

On the mathematical side, download this document with an outline of the theory I put together: RefOut

Fisheye: Executable or Text Version

Take any of photo and transform it using a Stereographic Projection. This is one form of algorithm used to make a fisheye lens.

Completely rewritten January 2018. I've left the BASIC version of the ASM routine in the Text version for reference. This could be a good exercise to study how a BASIC routine is rewritten as a self-contained ASM routine, compiled at runtime. It uses 80-bit floating point (tbyte) arithmetic.

Hue Changer: Executable or Text Version

Working with any BMP, JPG or GIF picture, this facility enables you to select a region of the picture and to then alter the colour hue of all sub-regions having a colour within a selected range.

This works very effectively even for example with a car-body with many reflections and shadows (see below).