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  • Your email address will not be published.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

  • Learn How A Global Entertainment Company Saw a 448% ROI Every business today uses software to manage systems, deliver products, and empower employees to do their jobs. But software inevitably breaks, and when it does, businesses lose money -- in the form of dissatisfied customers, missed SLAs or lost productivity. PagerDuty, an operations performance platform, solves this problem by helping operations engineers and developers more effectively manage and resolve incidents across a company's global operations. …

  • Today's agile organizations pose operations teams with a tremendous challenge: to deploy new releases to production immediately after development and testing is completed. To ensure that applications are deployed successfully, an automatic and transparent process is required. We refer to this process as Zero Touch Deployment™. This white paper reviews two approaches to Zero Touch Deployment--a script-based solution and a release automation platform. The article discusses how each can solve the key …

Most Popular Programming Stories

More for Developers

RSS Feeds