START OF HISTORY

(You can skip this stuff, if you have hurry ...)

I made an early version with GwBasic in early 90s, due to lack of commercial software. I tried to convert PC images with 256 colors to MSX2 in screen 8. That first version was very slow, took more than one minute to complete a picture.

Sometime later, I experimented with QBasic (included in Windows 95). I lost the source program, but some time later I made a slightly faster version with Qbasic (Windows 98 version).

In 2013, something happened in my job that allowed me to have much free time. Then I started programming again, a new program version. Years of MS-DOS were over, so I must find a programming language for Windows. And I found QB64.

So, since 2013, I've been programming, expanding and optimizing the program that currently has more than 1,500 lines of source code. Of course, add all the time dedicated tocreate, update and maintain this site, which is no picnic.

I hope you like it.

TECHNICAL DETAILS

(You can also skip this if you're not curious ...)

The MSX2 and above computers have a screen mode with 256 colors. But this colors are not programmable, they are set about a internal DAC with 8 bits. The two least significant bits (lsb) is blue component, the middle three is green component and the three most significant bits (msb) is red component. This is to reduce the size of the image inVRAM, facilitating the use of it.

Due to its limited color palette, the "color banding" effect occurs frequently. In the next picture you can see this effect on red component.

What's the reason for this program? Get the better results in an image made with equivalent colors. Thus greater precision is achieved in the image, producing a better brightness, contrast and final color. It is also possible to apply dithering, which produces the best results (mode 4 and 5). This applies to any kind of images, since the program accepts any size and color depth.

CURRENT VERSION

In the initial version you could convert an image with five different color modes, zoom and black and white mode. In the current version (2.0) has added a few more features, like two interlaced modes, creating cuts and the possibility to convert all images in a folder.

The operation is similar to the previous version, with the addition of these new features. For more information, download the manual at the end of the page, in the download section.

RECOMMENDED REQUIREMENTS

• Windows 32 or 64 bits.

• Minimal screen size: 1280px (width).

• 4 GB RAM.

• Free hard disc space: 6 MBi.

It is possible to operate the program with fewer features, such 512MB of RAM, but in those cases the program could not work at optimum speed. The reason for recommending 4GBi of RAM is to ensure that the operating system can run ease with other programs, that are running simultaneously. Of course everything is subject to the configuration of each computer.

DOWNLOADS

The download file is a compressed .ZIP. To start the program, decompress to a folder an run the .EXE file.

Program => BMP 256 v2.1

Manual => Español  =>  English