RLE (Run-Length-Encoding) Compression Routine in MFC for 256-Color Bitmaps

Environment: VC6, MFC

This is a RLE compression routine, written in MFC. I wrote this because I cannot find handy code for such a thing.

RLE compression is useful when saving a SIMPLE Windows bitmap. My implementation is rather stupid and not optimized. Therefore, if the source bitmap is complex (like the one in the demo app window shown below), you could even get a bigger bitmap file after compression.



Click here for a larger image.

The compression routine is wrapped in an MFC bitmap control class, CDVDBitmapControl, which you can put conveniently in a dialog. The usage is easy:

  1. Add a static control (say, IDC_STATIC_BITMAP) in the dialog for the bitmap control.
  2. Add an #include "DVDBitmapControl.h" in the header file of your dialog.
  3. Add a member variable (say, m_bmp) of type "CDVDBitmapControl" in your dialog class.
  4. In OnInitDialog(), add this line:
    m_bmp.SubclassDlgItem( IDC_STATIC_BITMAP, this).
  5. Call m_bmp.LoadBitmapFile(CString) to load a bitmap into the control.
  6. Call m_bmp.SaveBitmapFile(CString) to save a bitmap into an 8-bit RLE bitmap.

If you need only the compression code, you can just extract the CDVDBitmapControl::CompressInRLE8() and CDVDBitmapControl::EndOfLine() routines from "DVDBitmapControl.cpp". It is quite straightforward to use them.

I did not write the decompression part because the Windows API LoadImage() already does it.

PS: in the demo app, if the loaded bitmap is not in 256 colors, [Save] will not work.

Downloads

Download demo project - 20 Kb
Download source - 5 Kb


Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • 10 Rules that Make or Break Enterprise App Development Projects In today's app-driven world, application development is a top priority. Even so, 68% of enterprise application delivery projects fail. Designing and building applications that pay for themselves and adapt to future needs is incredibly difficult. Executing one successful project is lucky, but making it a repeatable process and strategic advantage? That's where the money is. With help from our most experienced project leads and software engineers, …

  • Between contractors and employees, there is a great deal of risk surrounding the privacy and security of sensitive data in the healthcare industry. When a breach is suspected, the law requires that healthcare organizations quickly launch an investigation to find the source and scope of the issue. These investigations can be quite costly, to say nothing of the penalties for the breach itself and the damage to reputation and brand. This white paper details new affordable software tools that can help healthcare …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds