Some instructions for using FractalCompression.exe

Once you start the application, you will see a screen that looks like Figure 1. Click the Open button, and you will see a window like in Figure 2.

Start by opening a bitmap. The bitmap must be 256 by 256 pixels, but can be black and white, gray scale or colour. To you use your own images, open them in paint first and crop them to 256 by 256.

Open the mena.bmp file and you will see something like Figure 3. Figure 3 shows the application during compression. Click the ‘Compress’ button to begin compression. Depending on the tolerance, compression can take a long time. As the application discovers ranges and domains whose rms error is less then the desired tolerence, enlargements of them are shown in the bottom right hand corner. The rotation that was used for the domain, as well as the resulting o, s and rms error values are shown above. To stop compression, click the ‘Stop’ button.

Once you have loaded an image, you may enter ‘Interactive Mode’. To do this, click the ‘Interactive Mode’ checkbox. You may now click on the image to compare domains and ranges manually. See Figure 4 for an example. Click the image once to select a range. Then click the image a second time to select a domain. To rotate the domain, do not move your mouse in between clicks. Comparisons between domain and range are done and the results are shown on the right.

In order to decompress, you must either complete a compression pass, or open a pre-created compression file. If you take the time to complete compression, the ‘Save’ button will become enabled. Click ‘Save’ to dump the Transformations that were generated during the compression to a Transformation file. Transformation files have the same filename as the bitmaps, with a ‘W’ appended to the end.

Click the Open button again and notice that the ‘Files of type’ box is a drop-down menu. Select ‘Transformations’ from the list, and browse to the Transformations directory. Select mena.bmp.W to load a transformation file. You will notice that the Decompression button becomes enables. Click it to perform decompression. You may change the number of iterations by clicking the Options button to enter the Options menu. In this menu you can also set the tolerance. Figure 6 shows a decompression being performed.

Finally, if either a decompression file is loaded, or a complete decompression has been completed, you may click the image to see which domains were mapped to which ranges. You do not have to enter ‘Interactive Mode’ to do this. Just load a bitmap, then either perform compression or load it’s corresponding transformation file. See Figure 7.