Question

Note: I am NOT a VB6 programmer – I’m an Android programmer responsible for an app used in manufacturing and I have a colleague responsible for a VB6 program that talks to my Android devices.

In the past our VB6 program sent Microsoft .bmps to the Android device, but now that we’re adding tablets to our product list, and want to send bigger images to take advantage of the tablet’s extra real-estate we find that .bmp’s are too big and clog up the network.

Eventually we’re replacing the old VB6 product with a .Net one, but until we do is there any way for VB6 to programmatically convert a bitmap to a JPEG? My colleague is unaware of one but I’ve always found S.O. to be very useful in my domains (Android, .Net) so I thought I’d try a VB6 question here.

Answer 1

In 2002 Microsoft released Windows® Image Acquisition Automation Library v2.0 Tool: Image acquisition and manipulation component for VB and scripting.

This can accept a .BMP or even a raw Windows 24-bit pixel bitmap (plus width & height) from a file or Byte array and convert them to JPEG, producing a file or Byte array result.

The Library is part of modern versions of Windows but can be installed into WinXP (SP1 or better).

Simple file-to-file example:

Dim ImgF As WIA.ImageFile
Dim ImgP As WIA.ImageProcess

Set ImgF = New WIA.ImageFile
ImgF.LoadFile "Zapotec.bmp"
Set ImgP = New WIA.ImageProcess
With ImgP
    .Filters.Add .FilterInfos!Convert.FilterID
    .Filters.Item(1).Properties!FormatID.Value = wiaFormatJPEG
    .Filters.Item(1).Properties!Quality.Value = 70
    Set ImgF = .Apply(ImgF)
End With
ImgF.SaveFile "Zapotec.jpg"