將圖像的像素由原來的1000*600縮小到500*300

[Hideal]

將jpg圖像的像素由原來的1000*600縮小到500*300,然後另存一個文件.如果可以設置它的質量那就最好了.

本站我搜索了一下也沒有找到這樣的程序例子.用panitpicture方法只會將圖的一部份存起來,達不到目的.

難道這樣問題也算難嗎?

[Hideal]

up

[zyl910]

本站我搜索了一下也沒有找到這樣的程序例子.用panitpicture方法只會將圖的一部份存起來,達不到目的.
=================================

别在同一个PictureBox中panitpicture！
将图像panitpicture到另一个PictureBox去
而且两者的AutoRedraw必须设为True（AutoRedraw=False时是在屏幕上画的，会被剪裁）


至于保存JPEG：
http://community.csdn.net/Expert/topic/3209/3209104.xml?temp=.9472772
★　完整的JPEG保存程序 与 高速在网络上传输图像程序

[zyl910]

難道這樣問題也算難嗎?
-------------------
是因为你现在的编程功力不够
某些东西不敢跟你说

比如：

利用插值算法实现图像的平滑缩放
讨论：http://search.csdn.net/Expert/topic/1183/1183347.xml?temp=.5059931
下载：http://www.aivisoft.net/Zyl910/zScale.zip

[Hideal]

唉。。原来是这么的easy!!!

晕啊。。。跳楼好了。。。。

[zyl910]

图像缩放程序的层次：

1：用PaintPicture缩放
2：用StretchBlt缩放
3：知道图像缩放原理，用SetPixelV逐点逐点算，速度非常慢
4：使用DIB图像处理技术加快图像处理速度，比3快70~100倍
5：考虑特殊CPU指令集优化算法，如MMX、3DNow!、SSE、SEE2等


楼主现在处于第一层次学习阶段

[Hideal]

請勿進行人身功擊!!!!!!!!!!!!!!!!!!!!!!!

做人的最起碼的道理.

雖然你的回答是我所想要的.但你的回答讓人非常的不快.

zyl910:現在處於經歷社會的第一層次學階段中,請先學會怎樣做人.(高手和菜鳥之間的差距是菜鳥起步的階段高手同樣走過,請不要回關笑你的過去)

不過還是很謝謝你.

[xxfeiyu]

用StretchBlt缩放
api申明里有

[Hideal]

承認你是高手,本人無地自容.

[zyl910]

我并不是想人身攻击

我只是想让楼主见识一下现在技术的发展层次
别被教科书迷惑了


我原来也对这这些超过自身层次的东西很反感
但现在仔细看了一下数学与物理学的发展后
我感觉自己以及某些人真的很肤浅：
比如某些人说现在数学与物理学没有发展
这实际上是现在数学与物理学发展的太快，已经超过普通人认识的层次
这就像我们还在地球上，太阳的光芒（学校教育）把一切遮盖住了，不知道现在的研究已经到了河外星系

大学数学算什么
微积分只是现在数学的基础
而且大学教的还是初等微积分

[zyl910]

注意：
PicClipD的ScaleMode=vbPixels
源图像是ImgSrc
目的图像是PicDest，注意它的属性
最关键的实现过程在CmdMake_Click


将下列内容复制到记事本，并保存为相应的文件


PicScale.vbp
--------------------
Type=Exe
Form=FrmMain.frm
Reference=*\G{00020430-0000-0000-C000-000000000046}#2.0#0#C:\WINDOWS\SYSTEM\STDOLE2.TLB#OLE Automation
Object={F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0; COMDLG32.OCX
Startup="FrmMain"
ExeName32="PicScale.exe"
Command32=""
Name="PicScale"
HelpContextID="0"
CompatibleMode="0"
MajorVer=1
MinorVer=0
RevisionVer=0
AutoIncrementVer=0
ServerSupportFiles=0
CompilationType=0
OptimizationType=0
FavorPentiumPro(tm)=0
CodeViewDebugInfo=0
NoAliasing=0
BoundsCheck=0
OverflowCheck=0
FlPointCheck=0
FDIVCheck=0
UnroundedFP=0
StartMode=0
Unattended=0
Retained=0
ThreadPerObject=0
MaxNumberOfThreads=1





FrmMain.frm
----------------------------------
VERSION 5.00
Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0"; "COMDLG32.OCX"
Begin VB.Form FrmMain
Caption = "简单图像文件缩放"
ClientHeight = 3195
ClientLeft = 165
ClientTop = 735
ClientWidth = 4680
HasDC = 0 'False
LinkTopic = "Form1"
ScaleHeight = 213
ScaleMode = 3 'Pixel
ScaleWidth = 312
StartUpPosition = 3 '窗口缺省
Begin MSComDlg.CommonDialog CDlgFile
Left = 2160
Top = 1320
_ExtentX = 847
_ExtentY = 847
_Version = 393216
End
Begin VB.PictureBox PicClipD
BackColor = &H8000000C&
HasDC = 0 'False
Height = 1695
Left = 2520
ScaleHeight = 109
ScaleMode = 3 'Pixel
ScaleWidth = 117
TabIndex = 8
TabStop = 0 'False
Top = 840
Width = 1815
Begin VB.PictureBox PicDest
AutoRedraw = -1 'True
BackColor = &H00FFFFFF&
BorderStyle = 0 'None
Height = 495
Left = 240
ScaleHeight = 33
ScaleMode = 3 'Pixel
ScaleWidth = 65
TabIndex = 9
TabStop = 0 'False
Top = 360
Width = 975
End
End
Begin VB.PictureBox PicClipS
BackColor = &H8000000C&
HasDC = 0 'False
Height = 1575
Left = 360
ScaleHeight = 101
ScaleMode = 3 'Pixel
ScaleWidth = 101
TabIndex = 7
TabStop = 0 'False
Top = 840
Width = 1575
Begin VB.Image ImgSrc
Height = 855
Left = 240
Top = 240
Width = 855
End
End
Begin VB.PictureBox PicToolBar
Align = 1 'Align Top
HasDC = 0 'False
Height = 495
Left = 0
ScaleHeight = 29
ScaleMode = 3 'Pixel
ScaleWidth = 308
TabIndex = 0
TabStop = 0 'False
Top = 0
Width = 4680
Begin VB.CommandButton CmdReset
Caption = "复位"
Height = 255
Left = 3960
TabIndex = 6
Top = 120
Width = 780
End
Begin VB.CommandButton CmdMake
Caption = "生成"
Height = 255
Left = 3120
TabIndex = 5
Top = 120
Width = 780
End
Begin VB.TextBox TxtHeight
Height = 270
Left = 2280
TabIndex = 4
Text = "Text1"
Top = 120
Width = 750
End
Begin VB.TextBox TxtWidth
Height = 270
Left = 720
TabIndex = 2
Text = "Text1"
Top = 120
Width = 750
End
Begin VB.Label LblHeight
AutoSize = -1 'True
Caption = "Height:"
Height = 180
Left = 1680
TabIndex = 3
Top = 120
Width = 630
End
Begin VB.Label LblWidth
AutoSize = -1 'True
Caption = "&Width:"
Height = 180
Left = 120
TabIndex = 1
Top = 120
Width = 540
End
End
Begin VB.Menu mnuFile
Caption = "文件(&F)"
Begin VB.Menu mnuOpen
Caption = "打开(&O)..."
End
Begin VB.Menu mnuSave
Caption = "保存(&S)..."
End
Begin VB.Menu mnuSep0_0
Caption = "-"
End
Begin VB.Menu mnuExit
Caption = "退出(&X)"
End
End
End
Attribute VB_Name = "FrmMain"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False

[zyl910]

Option Explicit

Private Const CtlSpace = 4 '控件之间的距离

Private Sub CmdMake_Click()
Dim nWidth As Long
Dim nHeight As Long

'得到数值
On Error GoTo ErrNum
nWidth = CLng(TxtWidth.Text)
nHeight = CLng(TxtHeight.Text)
On Error GoTo 0
If nWidth < 1 Or nHeight < 1 Then GoTo ErrNum

'改变大小
On Error GoTo ErrSetSize
PicDest.Move 0, 0, nWidth, nHeight
On Error GoTo 0

'取消PictureBox的缓存
Set PicDest.Picture = Nothing

'绘制图像
PicDest.PaintPicture ImgSrc, 0, 0, PicDest.ScaleWidth, PicDest.ScaleHeight

Exit Sub

ErrNum:
MsgBox "错误的数值！", vbCritical
Exit Sub

ErrSetSize:
MsgBox "无法创建这么大的图片！", vbCritical
Exit Sub

End Sub

Private Sub CmdReset_Click()
If ImgSrc.Picture.Type = vbPicTypeNone Then '无图片
TxtWidth.Text = CStr(1)
TxtHeight.Text = CStr(1)

CmdMake.Enabled = False

Else
TxtWidth.Text = CStr(ImgSrc.Width)
TxtHeight.Text = CStr(ImgSrc.Height)

CmdMake.Enabled = True

Call CmdMake_Click

End If

End Sub

Private Sub Form_Load()
'-- 初始化坐标定位
Dim SM_Me As Long
Dim SM_Tbr As Long
Dim nTemp As Long

SM_Me = Me.ScaleMode
SM_Tbr = PicToolBar.ScaleMode

'定位PicToolBar的高度
With PicToolBar
'计算边框大小
nTemp = Me.ScaleY(.Height, SM_Me, vbPixels) - .ScaleY(.ScaleHeight, SM_Tbr, vbPixels)
'计算PicToolBar应有高度
nTemp = nTemp + .ScaleY(TxtWidth.Height, SM_Tbr, vbPixels)
'设置高度
.Height = Me.ScaleY(nTemp, vbPixels, SM_Me)
End With

'定位PicToolBar内的控件
nTemp = PicToolBar.ScaleHeight
LblWidth.Move CtlSpace, (nTemp - LblWidth.Height) / 2
TxtWidth.Move LblWidth.Left + LblWidth.Width, 0
LblHeight.Move TxtWidth.Left + TxtWidth.Width + CtlSpace, (nTemp - LblWidth.Height) / 2
TxtHeight.Move LblHeight.Left + LblHeight.Width, 0, TxtHeight.Width, TxtWidth.Height
CmdMake.Move TxtHeight.Left + TxtHeight.Width + CtlSpace, 0, CmdMake.Width, TxtWidth.Height
CmdReset.Move CmdMake.Left + CmdMake.Width + CtlSpace, 0, CmdReset.Width, TxtWidth.Height

ImgSrc.Move 0, 0

PicDest.Move 0, 0

'--设置数值
Call CmdReset_Click

With CDlgFile
.CancelError = True
.Flags = cdlOFNOverwritePrompt Or cdlOFNHideReadOnly
.Filter = "Windows位图(*.bmp)|*.bmp|所有文件(*.*)|*.*"
End With

End Sub

Private Sub Form_Resize()
If Me.WindowState = 1 Then Exit Sub
On Error Resume Next

Dim nTemp As Long
nTemp = PicToolBar.Height
PicClipS.Move 0, nTemp, Me.ScaleWidth / 2, Me.ScaleHeight - nTemp
PicClipD.Move PicClipS.Width, nTemp, Me.ScaleWidth - PicClipS.Width, PicClipS.Height

End Sub

Private Sub mnuExit_Click()
Unload Me
End Sub

Private Sub mnuOpen_Click()
On Error Resume Next

CDlgFile.ShowOpen
If Err.Number Then Exit Sub '点了取消

'打开
Set ImgSrc.Picture = LoadPicture(CDlgFile.FileName)
If Err.Number Then
MsgBox "无法打开文件！", vbCritical
Exit Sub
End If

On Error GoTo 0

Call CmdReset_Click

End Sub

Private Sub mnuSave_Click()
On Error Resume Next

CDlgFile.ShowSave
If Err.Number Then Exit Sub '点了取消

'保存
SavePicture PicDest.Image, CDlgFile.FileName
If Err.Number Then
MsgBox "无法保存图片！", vbCritical
Exit Sub
End If

On Error GoTo 0

End Sub