About BMP2RLE
BMP2RLE - Bitmap Compression Utility

Table of Contents:

What is BMP2RLE?

How to use BMP2RLE

Adjusting the Color Palette

Changing the Windows start-up image

The advantages of registering BMP2RLE

The disadvantages of not registering BMP2RLE

For information, to report bugs, make suggestions...


Please contact:

Chris Velazquez

trailBLAZERS_SOFT.Ware

at CompuServe 74073,1566


What is BMP2RLE?

BMP2RLE is a handy little application which compresses Windows bitmaps into an abbreviated format called run-length encoding (RLE).  This is the format used for the Windows startup screen (such as the familiar blue Microsoft Windows plaque.)  You can use BMP2RLE to reformat your bitmaps from other drawing programs into new Startup screens.  The only requirement is that the drawing contains a maximum of 16 colors (of the 16.8 million available these days).

In addition to compression, BMP2RLE also allows the user to alter the color palette used by the bitmap.  This was added because other bitmap shareware utilities which ostensibly convert bitmaps to RLE also pick the default VGA palette and alter the colors of the original bitmap to their nearest VGA color, resulting in poor quality RLE files.  BMP2RLE extracts the original color that you specified in your paint program, and allows you to make changes as you desire.

Using BMP2RLE


Run-Length Encoding (RLE)

Rather than storing the information for every pixel of a bitmap in memory, a set of instructions for drawing the bitmap are stored instead. Windows can interpret these instructions quickly, thus making RLE format an efficient alternative to the normal .BMP formats generated by most painting programs.

The familiar blue "Microsoft Windows" startup screen is saved in the file C:\WINDOWS\SYSTEM\VGALOGO.RLE which is loaded into WIN.COM after each setup.  If you check, you'll notice it only occupies about 27 KB of disk space.  In normal bitmap formats, an image that large would occupy at least 10 times that much space.

RLE format is especially useful for bitmaps with a limited number of colors and relatively low complexity.  Images with a lot of shading and lighting, or complex "textures" do not compress much if at all, and images with many single color areas compress to 10%-1% (or less!) of their original size.  In many cases, recompressing an RLE format bitmap with a program like PKZIP results in even further compression, such that huge pictures consume mere kilobytes or less.  There are two formats available: RLE-4 and RLE-8.  RLE-4 supports a 4-bit color palette (16 colors) and RLE-8 supports an 8-bit (256 color) palette.  Each of these colors may be chosen from among the 16.7 million color selections offered by most SVGA graphics cards.

Using BMP2RLE


Using BMP2RLE
How to Use BMP2RLE

Using BMP2RLE is simple.

First create a masterpiece using your favorite drawing program (PBRUSH.EXE, perhaps?).  Save the image as a bitmap with the .BMP extension.

Open the bitmap file with BMP2RLE. (File menu)  The bitmap will be displayed and scanned, and salient information will be displayed.

Choose the Conversion menu.  Pick 4-Bit (RLE-4) or 8-Bit (RLE-8), depending on the number of actual colors in the original image.

Save the image using the .RLE or .BMP extension.

The compressed bitmap can be viewed by opening it next.

If you choose, you can alter the palette of the RLE format bitmap using the Palette Adjuster


Adjusting the Color Palette

This is also simple.  Only RLE format bitmaps work here though.

Method 1:  Simply choose the color you wish to change by clicking on the 16-color palette (RLE-4 bitmaps) or the pop-up 256-color palette (RLE-8 bitmaps), and it will appear in the box near the bottom.  Use the color sliders to change the color.  Swap the color with the original palette color.  Try out the new palette for looks, if you don't like it you can swap back to the original.

Method 2:  Click right on the picture of the bitmap on the color you wish to change.  That color will be displayed in the color box, and you can swap colors and try the new palette with the appropriate buttons.

Please note that the second method does not work well for video driver settings of less than 32K colors, since dithering is used to show the palette colors in lower color modes.  I personally favor the 800 x 600 x 64K colors driver for my SVGA video driver, which works nearly flawlessly, and the 640 x 480 x 16.7M color mode works perfectly.  High resolution/low color modes show spurious results, but then again, I usually sit at least six inches away from my monitor.

Modifying the Windows Startup Screen


Modifying the Startup Screen
Modifying the Windows Startup Screen

WinChange v4.0 is an excellent utility for changing your startup screen.  It is available from CompuServe' WinFun forum (GO WINFUN) and is very inexpensive to register.  Future versions of this bitmap compressor will likely include such utilities, but it will be hard to improve upon this fine piece of shareware.

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There is an alternative (free) and more complex approach which works just fine:

1) Create a new startup screen bitmap and convert it to RLE-4 format.  It must be less than 47 kB in size.

2) In the \WINDOWS\SYSTEM directory, rename a file called VGALOGO.RLE to VGALOGO.OLD.  (This may be CGA,EGA, or HERC instead of VGA)

3) Rename the new startup RLE-4 bitmap to VGALOGO.RLE and make sure it is in the \WINDOWS\SYSTEM directory.

4) Exit Windows.  Change to the \WINDOWS directory and type SETUP at the DOS prompt.

5) Choose C to continue.  Move the cursor to the Display drivers box and type <Enter>.

6) Scroll through the choices and choose the driver you were already using before you left Windows.  Type <Enter> to accept, then keep typing <Enter> until you arrive back at the DOS prompt.

7) Type WIN to return to Windows.  Your new startup screen should greet you!

8) The fonts may look strange at first.  To fix this, open  Control Panel (usually in the Main window), choose Fonts, and change the directory to \WINDOWS\SYSTEM.  The fonts will load into memory, and you can choose Select All to restore the fonts the way they were.  Exiting Windows and re-enetering will fix the fonts for good.

A Special Acknowledgement


Special thanks to Mike Mezaros, discoverer of this technique.

Rutgers The State University

L.P.O. 16062, P.O. Box 5064

New Brunswick, NJ 08903

GENIE:  M.MEZAROS

CompuServe: 75500,655.


Registration Information
Registering BMP2RLE

BMP2RLE is shareware, not public domain or freeware.  As such, it is protected by applicable copyright laws.  Use of this program to create a new startup screen or for any other bitmap compression constitutes ownership.

You may distribute this shareware freely, and test it for up to 15 days.  After that you should register this copy.  I have donated my time and expertise to create as useful and user-friendly of a program as possible, with the caveat that all proceeds are to help the construction of a building for Grace Church, of which I am a member.

To register, send a tax-deductible contribution to:

Grace Church

c/o Finance Committee

231 South Elliott St.

Chapel Hill, NC  27514

Registered users will receive the following:

*	A spiffier version of BMP2RLE with the following enhanced features:

- speedier graphics conversion

- Multiple bitmap viewing

- Intelligent color reduction

- Automatic search of compatible graphics files.

*	Regular updates to the original version.

*	Free support

*	A copy of "What every Visual Basic programmer should know about bitmaps"

*	Peace of mind, knowing that thou hast not stolen.


TrailBlazers cannot be held liable for what turmoil may befall you in the Hereafter.


About Grace Church

Grace Church is a non-denominational Christian church dedicated to the worship of the living God who rules above us yet resides among us.  The church is currently occupying a shopping center storefront and are trying to raise money to establish a permanent place of worship here in Chapel Hill.  We have purchased a plot of land and now we are raising money to erect a building.  I have donated my time to writing this shareware in hopes that it can provide some of the much needed funding for our goal.  Our head pastor is Jerry Daley, a Vietnam veteran, and a man truly fired up for God.  We are approximately 200 in number (excluding children) and are always willing to reach out to those hungry for the Word.  Our format mixes contemporary spiritual music with traditional beliefs.

We would love to have you visit us in worship if you are ever in the Research Triangle area of North Carolina.  We are located (as of 3/94) in Kroger Plaza in Chapel Hill, off of route 15-501, between Eastgate Plaza and University Mall.

God Bless You,

Chris Velazquez, PhD.

CompuServe: 74073,1566