vb中怎么把bmp图形压缩成jpg或者gif

[xxjmz_78]

急用，哪位大哥救我。

[lihonggen0]

Option Explicit
'============VB中实现BMP > GIF>JPG========================
Private Type RGBTRIPLE
rgbRed As Byte
rgbGreen As Byte
rgbBlue As Byte
End Type

Private Type RGBQUAD
rgbBlue As Byte
rgbGreen As Byte
rgbRed As Byte
rgbReserved As Byte
End Type

Private Type BITMAPINFOHEADER '40 bytes
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

Private Type BITMAPINFO256
bmiHeader As BITMAPINFOHEADER
bmiColors(0 To 255) As RGBQUAD
End Type

Private Type BITMAP '14 bytes
bmType As Long
bmWidth As Long
bmHeight As Long
bmWidthBytes As Long
bmPlanes As Integer
bmBitsPixel As Integer
bmBits As Long
End Type

Private Const BI_RGB = 0&

Private Declare Function CreateDCAsNull Lib "gdi32" Alias "CreateDCA" (ByVal lpDriverName As String, lpDeviceName As Any, lpOutput As Any, lpInitData As Any) As Long
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hDc As Long) As Long
Private Declare Function GetObjectAPI Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hDc As Long, ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal x As Long, ByVal Y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hDc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function GetDIBits Lib "gdi32" (ByVal aHDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As Long, lpBits As Any, lpBI As BITMAPINFO256, ByVal wUsage As Long) As Long
Private Declare Function CreateDIBSection256 Lib "gdi32" Alias "CreateDIBSection" (ByVal hDc As Long, pBitmapInfo As BITMAPINFO256, ByVal un As Long, lplpVoid As Long, ByVal handle As Long, ByVal dw As Long) As Long
Private Const DIB_RGB_COLORS = 0

Private Declare Function GetFileAttributes Lib "kernel32" Alias "GetFileAttributesA" (ByVal lpFileName As String) As Long
'============================GIF STAFF================

Private Type GifScreenDes criptor
logical_screen_width As Integer
logical_screen_height As Integer
flags As Byte
background_color_index As Byte
pixel_aspect_ratio As Byte
End Type

Private Type GifImageDes criptor
Left As Integer
Top As Integer
Width As Integer
Height As Integer
Format As Byte 'ImageFormat
End Type

Const GIF87a = "GIF87a"
Const GifTerminator As Byte = &H3B
Const ImageSeparator As Byte = &H2C
Const CHAR_BIT = 8
Const CodeSize As Byte = 9
Const ClearCode = 256
Const EndCode As Integer = 257
Const FirstCode = 258
Const LastCode As Integer = 511
Const MAX_CODE = LastCode - FirstCode

Private colTable As New Collection
Private fn As Integer
Private gifPalette(0 To 255) As RGBTRIPLE
Private bit_position As Integer
Private code_count As Integer
Private data_buffer(255) As Byte
Private aPower2(31) As Long
Private picWidth As Long, picHeight As Long
Private IsBusy As Boolean
Public Event Progress(ByVal Percents As Integer)

[lihonggen0]

Public Function SaveGIF(ByVal pic As StdPicture, ByVal sFileName As String, Optional hDc As Long = 0) As Boolean
If IsBusy Then Exit Function
Dim scr As GifScreenDes criptor, im As GifImageDes criptor
Dim bi As BITMAPINFO256, bm As BITMAP
Dim hDCScn As Long, OldObj As Long, Src_hDc As Long
Dim hDib256 As Long, hDC256 As Long, OldObj256 As Long
Dim buf() As Byte, data As Byte
Dim I As Long, J As Long
Dim intCode As Integer, nCount As Integer
Dim sPrefix As String, sByte As String
Dim tempPic As StdPicture
IsBusy = True
'get image size and allocate buffer memory
Call GetObjectAPI(pic, Len(bm), bm)
picWidth = bm.bmWidth
picHeight = bm.bmHeight
ReDim buf(CLng(((picWidth + 3) \ 4) * 4), picHeight) As Byte
'Prepare DC for paintings
hDCScn = CreateDCAsNull("DISPLAY", ByVal 0&, ByVal 0&, ByVal 0&)
hDC256 = CreateCompatibleDC(hDCScn)
If hDc = 0 Then
Src_hDc = CreateCompatibleDC(hDCScn)
OldObj = SelectObject(Src_hDc, pic)
Else
Src_hDc = hDc
End If
DeleteDC hDCScn

'Since GIF works only with 256 colors, reduce color depth to 256
'This sample use simpliest HalfTone palette to reduce color depth
'If you want advanced color manipulation with web-safe palettes or
'optimal palette with the specified number of colors using octree
'quantisation, visit http://vbaccelerator.com/codelib/gfx/octree.htm

If bm.bmBitsPixel <> 8 Then hDib256 = CreateDib256(hDC256, bi)
If hDib256 <> 0 Then
OldObj256 = SelectObject(hDC256, hDib256)
Call BitBlt(hDC256, 0, 0, picWidth, picHeight, Src_hDc, 0, 0, vbSrcCopy)
For I = 0 To picHeight - 1
Call GetDIBits(hDC256, hDib256, I, 1, buf(0, picHeight - I), bi, 0)
Next
Else
With bi.bmiHeader
.biSize = Len(bi.bmiHeader)
.biWidth = picWidth
.biHeight = picHeight
.biPlanes = 1
.biBitCount = 8
.biCompression = BI_RGB
End With
For I = 0 To picHeight - 1
Call GetDIBits(Src_hDc, pic, I, 1, buf(0, picHeight - I), bi, 0)
Next
End If
For I = 0 To 255
gifPalette(I).rgbBlue = bi.bmiColors(I).rgbBlue
gifPalette(I).rgbGreen = bi.bmiColors(I).rgbGreen
gifPalette(I).rgbRed = bi.bmiColors(I).rgbRed
Next
fn = FreeFile
scr.background_color_index = 0
scr.flags = &HF7 '256-color gif with global color map
scr.pixel_aspect_ratio = 0

im.Format = &H7 'GlobalNonInterlaced
im.Height = picHeight
im.Width = picWidth

If FileExists(sFileName) Then Kill sFileName

Open sFileName For Binary As fn
'Write GIF header and header info
Put #fn, , GIF87a
Put #fn, , scr
Put #fn, , gifPalette
Put #fn, , ImageSeparator
Put #fn, , im
data = CodeSize - 1
Put #fn, , data
data_buffer(0) = 0
bit_position = CHAR_BIT
'Process pixels data using LZW - GIF compression
For I = 1 To picHeight
Reinitialize
sPrefix = ""
intCode = buf(0, I)
On Error Resume Next
For J = 1 To picWidth - 1
sByte = MyFormat(buf(J, I))
sPrefix = sPrefix & sByte
intCode = colTable(sPrefix)
If Err <> 0 Then 'Prefix wasn't in collection - save it and output code
nCount = colTable.count
If nCount = MAX_CODE Then Reinitialize
colTable.Add nCount + FirstCode, sPrefix
OutputBits intCode, CodeSize
sPrefix = sByte
intCode = buf(J, I)
Err.Clear
End If
Next
OutputBits intCode, CodeSize
If I Mod 10 = 0 Then
RaiseEvent Progress(I * 100 / picHeight)
DoEvents
End If
Next
OutputCode (EndCode)
For I = 0 To data_buffer(0)
Put #fn, , data_buffer(I)
Next
data = 0
Put #fn, , data
Put #fn, , GifTerminator
Close fn
Erase buf
If hDc = 0 Then
SelectObject Src_hDc, OldObj
DeleteDC Src_hDc
End If
SelectObject hDC256, OldObj256
DeleteObject hDib256
DeleteDC hDC256
SaveGIF = True
IsBusy = False
End Function
Private Sub OutputBits(Value As Integer, count As Integer)
Dim I As Integer, bit As Integer
Do While I < count
If bit_position >= CHAR_BIT Then
If data_buffer(0) = 255 Then
Put #fn, , data_buffer
data_buffer(0) = 1
Else
data_buffer(0) = data_buffer(0) + 1
End If
data_buffer(data_buffer(0)) = 0
bit_position = 0
End If
bit = Sgn(Power2(I) And Value)
If bit > 0 Then data_buffer(data_buffer(0)) = Power2(bit_position) Or data_buffer(data_buffer(0))
bit_position = bit_position + 1
I = I + 1
Loop
End Sub

Private Sub OutputCode(code As Integer)
code_count = code_count + 1
If code_count > LastCode Then
code_count = FirstCode
Call OutputBits(ClearCode, CodeSize)
ClearTable
End If
Call OutputBits(code, CodeSize)
End Sub

Private Sub ClearTable()
Set colTable = Nothing
Set colTable = New Collection
End Sub

Private Sub Reinitialize()
ClearTable
Call OutputBits(ClearCode, CodeSize)
End Sub

Private Function FileExists(ByVal strPathName As String) As Boolean
Dim af As Long
af = GetFileAttributes(strPathName)
FileExists = (af <> -1)
End Function

[lihonggen0]

Private Function Power2(ByVal I As Integer) As Long
If aPower2(0) = 0 Then
aPower2(0) = &H1&
aPower2(1) = &H2&
aPower2(2) = &H4&
aPower2(3) = &H8&
aPower2(4) = &H10&
aPower2(5) = &H20&
aPower2(6) = &H40&
aPower2(7) = &H80&
aPower2(8) = &H100&
aPower2(9) = &H200&
aPower2(10) = &H400&
aPower2(11) = &H800&
aPower2(12) = &H1000&
aPower2(13) = &H2000&
aPower2(14) = &H4000&
aPower2(15) = &H8000&
aPower2(16) = &H10000
aPower2(17) = &H20000
aPower2(18) = &H40000
aPower2(19) = &H80000
aPower2(20) = &H100000
aPower2(21) = &H200000
aPower2(22) = &H400000
aPower2(23) = &H800000
aPower2(24) = &H1000000
aPower2(25) = &H2000000
aPower2(26) = &H4000000
aPower2(27) = &H8000000
aPower2(28) = &H10000000
aPower2(29) = &H20000000
aPower2(30) = &H40000000
aPower2(31) = &H80000000
End If
Power2 = aPower2(I)
End Function

Private Function MyFormat(ByVal s As String) As String
MyFormat = Right$("00" & s, 3)
End Function

Private Function CreateDib256(ByVal h_Dc As Long, bi As BITMAPINFO256) As Long
Dim lScanSize As Long
Dim lptr As Long, lIndex As Long
Dim r As Long, g As Long, b As Long
Dim rA As Long, gA As Long, bA As Long
With bi.bmiHeader
.biSize = Len(bi.bmiHeader)
.biWidth = picWidth
.biHeight = picHeight
.biPlanes = 1
.biBitCount = 8
.biCompression = BI_RGB
lScanSize = (picWidth + picWidth Mod 4)
.biSizeImage = lScanSize * picHeight
End With
' Halftone 256 colour palette
For b = 0 To &H100 Step &H40
If b = &H100 Then
bA = b - 1
Else
bA = b
End If
For g = 0 To &H100 Step &H40
If g = &H100 Then
gA = g - 1
Else
gA = g
End If
For r = 0 To &H100 Step &H40
If r = &H100 Then
rA = r - 1
Else
rA = r
End If
With bi.bmiColors(lIndex)
.rgbRed = rA: .rgbGreen = gA: .rgbBlue = bA
End With
lIndex = lIndex + 1
Next r
Next g
Next b
CreateDib256 = CreateDIBSection256(h_Dc, bi, DIB_RGB_COLORS, lptr, 0, 0)
End Function

[sxs69]

www.dapha.net/down
www.vbgood.com

[Vii]

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[rainstormmaster]

不用找了，用代码实现的就是上面lihonggen0(李洪根,用.NET，标准答案来了) 写的，可惜没有实现save to jpg，其它的都是借助第三方控件实现的

[wingchi]

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[wingchi]

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