VB6 - compress a bitmap to png or jpg without any third party dlls?

[Appledrop]

edit: solved. had to use GDI+ call - GdipSaveImageToStream function


Hi, I have a very large byte array which represents a bitmap image (if you wrote the byte array out to a file the picture would open properly)
But.. Its too big.. I want to compress the bitmap array into an array containing a jpeg or png image.
Does anyone have any idea how this could be done, without using any external dlls except those included in windows or ocx files?
I was thinking GDI.. But I have no idea how to do this...

anyone got any help please

 

[Ken g6]

Windows bitmaps are very simple files. PNGs and Jpegs are not.

Why must you avoid external dlls? I seem to recall VB3 was able to interface with external dlls.

 

[Appledrop]

Originally posted by: Ken g6
Windows bitmaps are very simple files. PNGs and Jpegs are not.

Why must you avoid external dlls? I seem to recall VB3 was able to interface with external dlls.

i mean I dont want to have to distribute seperate files along with the executable :/
Is achieving what I want harder than I thought it should be? Blahh.. 3 meg pictures are no good :brokenheart:

 

[Ken g6]

How about a different file format? Before Jpeg was even a standard, there was the PCX file format. It uses only run-length encoding, so it's no good for photos, but it's OK for computer-generated pictures.

Here's Wikipedia's article
Here's some assembly decompression code and other information.
Here's the official reference manual

P.S. Your task would have been a lot easier if you were using a .NET-based version of Visual Basic, like this one.