如何将bmp转换为vb6中的jpg

Question

如何将bmp转换为vb6中的jpg？

Answer 1

检查这个link

'Convert BMP to JPG with this code. (Note: Requires vic32.dll available from 
'http://www.catenary.com/) 

'PLACE ALL THIS IN A NEW MODULE 

Declare Function bmpinfo Lib "VIC32.DLL" (ByVal Fname As String, bdat As BITMAPINFOHEADER) As Long 
Declare Function allocimage Lib "VIC32.DLL" (image As imgdes, ByVal wid As Long, ByVal leng As Long, ByVal BPPixel As Long) As Long 
Declare Function loadbmp Lib "VIC32.DLL" (ByVal Fname As String, desimg As imgdes) As Long 
Declare Sub freeimage Lib "VIC32.DLL" (image As imgdes) 
Declare Function convert1bitto8bit Lib "VIC32.DLL" (srcimg As imgdes, desimg As imgdes) As Long 
Declare Sub copyimgdes Lib "VIC32.DLL" (srcimg As imgdes, desimg As imgdes) 
Declare Function savejpg Lib "VIC32.DLL" (ByVal Fname As String, srcimg As imgdes, ByVal quality As Long) As Long 



' Image descriptor 
Type imgdes 
    ibuff As Long 
    stx As Long 
    sty As Long 
    endx As Long 
    endy As Long 
    buffwidth As Long 
    palette As Long 
    colors As Long 
    imgtype As Long 
    bmh As Long 
    hBitmap As Long 
End Type 

Type BITMAPINFOHEADER 
    biSize As Long 
    biWidth As Long 
    biHeight As Long 
    biPlanes As Integer 
    biBitCount As Integer 
    biCompression As Long 
    biSizeImage As Long 
    biXPelsPerMeter As Long 
    biYPelsPerMeter As Long 
    biClrUsed As Long 
    biClrImportant As Long 
End Type 

'PLACE THIS IN YOUR FORM DECLERATIONS 

Private Sub ConvertToJPEG(bmp_fname As String, jpg_fname As String, Optional quality As Long) 
    Dim tmpimage As imgdes ' Image descriptors 
    Dim tmp2image As imgdes 
    Dim rcode As Long 
    'Dim quality As Long 
    Dim vbitcount As Long 
    Dim bdat As BITMAPINFOHEADER ' Reserve space for BMP struct 
    'Dim bmp_fname As String 
    'Dim jpg_fname As String 

    'bmp_fname = "test.bmp" 
    'jpg_fname = "test.jpg" 

    If quality = 0 Then quality = 75 

    ' Get info on the file we're to load 
    rcode = bmpinfo(bmp_fname, bdat) 
    If (rcode <> NO_ERROR) Then 
    msgbox "error: Unable to get file info" 
    Exit Sub 
    End If 

    vbitcount = bdat.biBitCount 
    If (vbitcount >= 16) Then ' 16-, 24-, or 32-bit image is loaded into 24-bit buffer 
    vbitcount = 24 
    End If 

    ' Allocate space for an image 
    rcode = allocimage(tmpimage, bdat.biWidth, bdat.biHeight, vbitcount) 
    If (rcode <> NO_ERROR) Then 
    msgbox "error: Not enough memory" 
    Exit Sub 
    End If 

    ' Load image 
    rcode = loadbmp(bmp_fname, tmpimage) 
    If (rcode <> NO_ERROR) Then 
    freeimage tmpimage ' Free image on error 
    msgbox "error: Cannot load file" 
    Exit Sub 
    End If 

    If (vbitcount = 1) Then ' If we loaded a 1-bit image, convert to 8-bit grayscale 
     ' because jpeg only supports 8-bit grayscale or 24-bit color images 
    rcode = allocimage(tmp2image, bdat.biWidth, bdat.biHeight, 8) 
    If (rcode = NO_ERROR) Then 
     rcode = convert1bitto8bit(tmpimage, tmp2image) 
     freeimage tmpimage ' Replace 1-bit image with grayscale image 
     copyimgdes tmp2image, tmpimage 
    End If 
    End If 

    ' Save image 
    rcode = savejpg(jpg_fname, tmpimage, quality) 
    freeimage tmpimage 
    Kill bmp_fname 
    msgbox "picture saved: " & jpg_fname 

End Sub 

Answer 2

From here:

虽然有各种可用来保存其它格式的文件第三方控件，这些往往是“每座”有不可接受的许可政策及可不得了昂贵。本文介绍如何使用免费的JPEG DLL库来保存VB图片。

PS：支付$ 500，像VIC32库只保存JPG图像似乎太多...

Answer 3

与ImageMagick船舶它，这样做

shell "convert.exe image.bmp image.jpg" 

Answer 4

您可以use GDI+从VB6到保存为JPG。

Answer 5

那么，对于XP SP1和更高版本，您可以使用提供的工具：WIA 2.0库。

为了简单地转换BMP为JPG你可以去掉近一半在这里行：

Option Explicit 
' 
'Requires a reference to: 
' Microsoft Windows Image Acquisition Library v2.0 
' 

Private Const TIFF_LZW As String = "LZW" 
Private Const TIFF_RLE As String = "RLE"  'Pixel Depth must be 1. 
Private Const TIFF_CCITT3 As String = "CCITT3" 'Pixel Depth must be 1. 
Private Const TIFF_CCITT4 As String = "CCITT4" 'Pixel Depth must be 1. 
Private Const TIFF_Uncompressed As String = "Uncompressed" 

Private Sub ImgConvert(_ 
    ByVal InFileName As String, _ 
    ByVal OutFileName As String, _ 
    ByVal OutFormat As String, _ 
    Optional ByVal Quality As Integer = 100, _ 
    Optional ByVal Compression As String = TIFF_LZW) 

    Dim Img As WIA.ImageFile 
    Dim ImgProc As WIA.ImageProcess 

    Set Img = New WIA.ImageFile 
    Img.LoadFile InFileName 
    Set ImgProc = New WIA.ImageProcess 
    With ImgProc.Filters 
     .Add ImgProc.FilterInfos("Convert").FilterID 
     .Item(1).Properties("FormatID").Value = OutFormat 
     If OutFormat = wiaFormatJPEG Then 
      .Item(1).Properties("Quality").Value = Quality 
     ElseIf OutFormat = wiaFormatTIFF Then 
      .Item(1).Properties("Compression").Value = Compression 
     End If 
    End With 
    Set Img = ImgProc.Apply(Img) 

    On Error Resume Next 
    Kill OutFileName 
    On Error GoTo 0 
    Img.SaveFile OutFileName 
End Sub 

Private Sub Main() 
    ImgConvert "sample.bmp", "sample.jpg", wiaFormatJPEG, 70 
    ImgConvert "sample.bmp", "sample.gif", wiaFormatGIF 
    ImgConvert "sample.bmp", "sample.png", wiaFormatPNG 
    ImgConvert "sample.bmp", "sample.tif", wiaFormatTIFF, , TIFF_Uncompressed 
    MsgBox "Complete" 
End Sub 

对于XP，你需要将它部署：Windows® Image Acquisition Automation Library v2.0 Tool: Image acquisition and manipulation component for VB and scripting。

对于以后的任何事情，它已经是操作系统的一部分。

Answer 6

简单！
1）这是最短方法：如果你想转换为任何格式（有/无压缩）

SavePicture(LoadPicture("c:\YourFile.BMP"),"c:\YourFile.JPG") 

2），我建议FFMpeg。

Shell("ffmpeg.exe -i YourFile.bmp -q <qualityNumber*> ConverTo.Any") 

* write ffmpeg /？在cmd知道使用情况