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vb.net改分辨率 vbox调整分辨率
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vb.net保存图片时如何调整其分辨率
保存前加一句 myImage2.SetResolution(300, 300) 你设置的bMape不是保存的主画布 所以无效,设置分辨率就是 SetResolution(X,Y)
vb.net如何获取屏幕分辨率从而设置窗体大小
默认单位是像素
96是系统vb.net改分辨率的一种设定vb.net改分辨率,每英寸vb.net改分辨率的点数vb.net改分辨率,是系统界面用小字体时的设置
用像素数除以dpi没有意义
VB.NET中设定窗体大小
窗体初始化时,设定Windowstate= maximized.
窗体分辨率仍然可以设成1920x1080。设计元素的时候拖拽,或者使用代码初始化控件。
VB.NET设置屏幕分辨率、颜色位数、刷新率 实例代码
这篇文章介绍了VB.NET设置屏幕分辨率、颜色位数、刷新率
实例代码,有需要的朋友可以参考一下
复制代码
代码如下:
Private
Declare
Function
GetDeviceCaps
Lib
"gdi32"
(ByVal
hdc
As
Long,
ByVal
nIndex
As
Long)
As
Long
Private
Declare
Function
ChangeDisplaySettings
Lib
"user32"
Alias
"ChangeDisplaySettingsA"
(lpDevMode
As
Any,
ByVal
dwflags
As
Long)
As
Long
Private
Const
CCDEVICENAME
As
Long
=
32
Private
Const
CCFORMNAME
As
Long
=
32
Private
Const
DM_BITSPERPEL
As
Long
=
H40000
Private
Const
DM_PELSWIDTH
As
Long
=
H80000
Private
Const
DM_PELSHEIGHT
As
Long
=
H100000
Private
Const
DM_DISPLAYFLAGS
As
Long
=
H200000
Private
Const
DM_DISPLAYFREQUENCY
=
H400000
Private
Const
CDS_FORCE
As
Long
=
H80000000
Private
Const
BITSPIXEL
As
Long
=
12
Private
Const
HORZRES
As
Long
=
8
Private
Const
VERTRES
As
Long
=
10
Private
Const
VREFRESH
=
116
Private
Type
DEVMODE
dmDeviceName
As
String
*
CCDEVICENAME
dmSpecVersion
As
Integer
dmDriverVersion
As
Integer
dmSize
As
Integer
dmDriverExtra
As
Integer
dmFields
As
Long
dmOrientation
As
Integer
dmPaperSize
As
Integer
dmPaperLength
As
Integer
dmPaperWidth
As
Integer
dmScale
As
Integer
dmCopies
As
Integer
dmDefaultSource
As
Integer
dmPrintQuality
As
Integer
dmColor
As
Integer
dmDuplex
As
Integer
dmYResolution
As
Integer
dmTTOption
As
Integer
dmCollate
As
Integer
dmFormName
As
String
*
CCFORMNAME
dmUnusedPadding
As
Integer
dmBitsPerPel
As
Integer
dmPelsWidth
As
Long
dmPelsHeight
As
Long
dmDisplayFlags
As
Long
dmDisplayFrequency
As
Long
End
Type
Private
Sub
cmdChangeDesktopMode_Click()
Dim
DM
As
DEVMODE
With
DM
.dmPelsWidth
=
CInt(txtNewWidth.Text)
.dmPelsHeight
=
CInt(txtNewHeight.Text)
.dmBitsPerPel
=
CInt(txtNewColor.Text)
.dmDisplayFrequency
=
CInt(txtNewFreq.Text)
.dmFields
=
DM_PELSWIDTH
Or
DM_PELSHEIGHT
Or
DM_BITSPERPEL
Or
DM_DISPLAYFREQUENCY
.dmSize
=
LenB(DM)
End
With
If
ChangeDisplaySettings(DM,
CDS_FORCE)
Then
MsgBox
"错误!不支持此模式!"
End
If
End
Sub
Private
Sub
Form_Load()
txtOldWidth.Text
=
GetDeviceCaps(Me.hdc,
HORZRES)
txtOldHeight.Text
=
GetDeviceCaps(Me.hdc,
VERTRES)
txtOldColor.Text
=
GetDeviceCaps(Me.hdc,
BITSPIXEL)
txtOldFreq.Text
=
GetDeviceCaps(Me.hdc,
VREFRESH)
End
Sub
vb.net 怎样将窗体和所有控件根据电脑分辨率固定?
使用SplitContainer1控件不就行了vb.net改分辨率,SplitContainer1控件vb.net改分辨率的Fixedpanel属性设置为Panel1\x0d\x0aSplitContainer1vb.net改分辨率的Panel2里面再放置一个SplitContainer2\x0d\x0aSplitContainer2控件的Fixedpanel属性设置为Panel2\x0d\x0a二个SplitContainer设置为水平折为器方向\x0d\x0a至于播放器控件就放在SplitContainer2控件Panel1里面\x0d\x0a播放器控件DOCK设置为FILL\x0d\x0a\x0d\x0a这样不管放大缩小界面vb.net改分辨率,播放器控件总是自适应窗体大小而菜单按钮总是在最边缘
VB中如何修改jpg图片的dpi
你可以使用二次线形插值vb.net改分辨率的方法:
Public Sub ZoomImage(ByVal OutPutWidth As Long, ByVal OutputHeight As Long)
Dim I As Long
Dim L As Long
Dim X As Long
Dim Y As Long
Dim Xb As Long
Dim Yb As Long
Dim Xe As Long
Dim Ye As Long
Dim M As Integer
Dim N As Integer
Dim CurR As Long
Dim CurG As Long
Dim CurB As Long
Dim NxtR As Integer
Dim NxtG As Integer
Dim NxtB As Integer
Dim DR As Single
Dim DG As Single
Dim DB As Single
Dim DRt As Single
Dim DGt As Single
Dim DBt As Single
Dim Xratio As Single
Dim Yratio As Single
Dim CurStep As Single
Dim NxtStep As Single
Dim NegN As Single
On Error GoTo ErrLine
If Not CanZoom Then Exit Sub
Done = False
OutPutWid = OutPutWidth - 1
OutPutHei = OutputHeight - 1
I = (Bits \ 8) - 1
ReDim ColTmp(I, InPutWid, OutPutHei) '先从Y方向进行缩放处理,结果保存在此中间数组内
ReDim ColOut(I, OutPutWid, OutPutHei)
Xratio = OutPutWid / InPutWid
Yratio = OutPutHei / InPutHei
TimeZoom = timeGetTime
NegN = 1 / Int(Yratio + 1)
For X = 0 To InPutWid
CurR = ColVal(0, X, 0)
CurG = ColVal(1, X, 0)
CurB = ColVal(2, X, 0)
CurStep = 0
NxtStep = 0
For Y = 0 To InPutHei - 1
NxtStep = CurStep + Yratio
Yb = CurStep
Ye = NxtStep
N = Ye - Yb
ColTmp(0, X, Yb) = CurR
ColTmp(1, X, Yb) = CurG
ColTmp(2, X, Yb) = CurB
M = Y + 1
NxtR = ColVal(0, X, M)
NxtG = ColVal(1, X, M)
NxtB = ColVal(2, X, M)
If N 1 Then
DRt = (NxtR - CurR) * NegN
DGt = (NxtG - CurG) * NegN
DBt = (NxtB - CurB) * NegN
DR = 0
DG = 0
DB = 0
For L = Yb + 1 To Ye - 1
DR = DR + DRt
DG = DG + DGt
DB = DB + DBt
ColTmp(0, X, L) = CurR + DR
ColTmp(1, X, L) = CurG + DG
ColTmp(2, X, L) = CurB + DB
Next
End If
CurStep = NxtStep
CurR = NxtR
CurG = NxtG
CurB = NxtB
Next
ColTmp(0, X, OutPutHei) = NxtR
ColTmp(1, X, OutPutHei) = NxtG
ColTmp(2, X, OutPutHei) = NxtB
Next
NegN = 1 / Int(Xratio + 1)
For Y = 0 To OutPutHei
CurR = ColTmp(0, 0, Y)
CurG = ColTmp(1, 0, Y)
CurB = ColTmp(2, 0, Y)
CurStep = 0
NxtStep = 0
For X = 0 To InPutWid - 1
NxtStep = CurStep + Xratio
Xb = CurStep
Xe = NxtStep
N = Xe - Xb
ColOut(0, Xb, Y) = CurR
ColOut(1, Xb, Y) = CurG
ColOut(2, Xb, Y) = CurB
M = X + 1
NxtR = ColTmp(0, M, Y)
NxtG = ColTmp(1, M, Y)
NxtB = ColTmp(2, M, Y)
If N 1 Then
DRt = (NxtR - CurR) * NegN
DGt = (NxtG - CurG) * NegN
DBt = (NxtB - CurB) * NegN
DR = 0
DG = 0
DB = 0
For L = Xb + 1 To Xe - 1
DR = DR + DRt
DG = DG + DGt
DB = DB + DBt
ColOut(0, L, Y) = CurR + DR
ColOut(1, L, Y) = CurG + DG
ColOut(2, L, Y) = CurB + DB
Next
End If
CurStep = NxtStep
CurR = NxtR
CurG = NxtG
CurB = NxtB
Next
ColOut(0, OutPutWid, Y) = NxtR
ColOut(1, OutPutWid, Y) = NxtG
ColOut(2, OutPutWid, Y) = NxtB
Next
Done = True
TimeZoom = timeGetTime - TimeZoom
CanPut = True
Exit Sub
ErrLine:
MsgBox Err.Description
End Sub
全局变量定义vb.net改分辨率:
Dim ColTmp() As Byte '用于保存插值中间变量
Dim OutPutHei As Long '要插值vb.net改分辨率的目标高度
Dim OutPutWid As Long '要插值的目标宽度
Public TimeZoom As Long '插值运算使用的时间
简单解释一下关于二次线性插值算法。
(为vb.net改分辨率了说明算法本身,我们只计算这个图片的红色分量,因为红绿蓝三种颜色的计算方法完全相同)
假设我们有一个很简单的图片,图片只有4个像素(2*2)
A B
C D
现在我们要把这个图片插值到9个像素:3*3
A ab B
ac abcd bd
C cd D
其中大写的字母代表原来的像素,小写字母代表插值得到的新像素。
想必看到这个图,大家心里已经有了这个算法了。
ab=(A+B) / 2
cd=(C+D) / 2
ac=(A+C) / 2
bd=(B+D) / 2
abcd=(ab+cd) / 2=(A+B+C+D) / 4
推导:
ab= A + (B-A) / 2
cd=C +(D-C) / 2
...
很简单,对吧,先从一个方向把只涉及两个原始像素的新像素算出来。我们这里假定先计算水平方向。而在算垂直方向的插值的时候,因为ab和cd已经在前面算好了,所以abcd的计算也和计算ac和bd没有任何区别了。
有可能为有朋友已经想到把原来的图像插值到4*4或5*5的方法了。
A ab1 ab2 B
ac1 ab1cd11 ab2cd21 bd1
ac2 ab1cd12 ab2cd22 bd2
C cd1 cd2 D
推导:
ab1 = A + (B-A) * 1 / 3
ab2 = A + (B-A) * 2 / 3 =ab1+(B-A) / 3
cd1 = C + (D-C) * 1 / 3
cd1 = C + (D-C) * 2 / 3 =cd1+(D-C) / 3
...
以A和B为例,先求出原始像素的差(A-B)再算出每一步的递增量(A-B) / 3;然后每一个新的点就是在前面那个点的值加上这个递增量就是了。
这里我们假设A=100, B=255 放大倍率为3,水平方向插值;先计算出原始像素的差:(B-A) = 255-100 =155
再计算出水平方向每一步的递增量:(A-B) / 3=155 / 3 = 51.7
这里我们用一个变量DRt来记录这个递增量(这里只用红色来做例子)
ab1 = A + DRt = 100+51.7 =151
ab2 = ab1 + DRt = 151+51.7 = 202
好了,其实二次线性算法就是这么一个东西,并不复杂。或许有写朋友会对于我给出的代码产生疑问。很简单的一个算法为什么要写这么多代码。
其实答案很简单:为了提高速度。
在VB中“+”和“-”永远是最快的,“*”要比“/”和“\”快。不论是什么类型的变量都是这样的。
下面再来分析一下我的程序。
在我的程序中把两个方向的插值分解成了两个单独的部分。
先把
A B
C D
变成:
A ab1...abN B
C cd1...cdN D
再变成:
A ab1...abN B
ac1 ............. db1
... ............ ...
acN .............. bdN
C cd1...cdN D
这两个方向的插值算法完全相同
而Xratio 和Yratio 这两个变量则用来记录水平方向和垂直方向的放大倍率。所以这个过程也能够让图像缩放不按照原始的纵横比进行。
好了,将这个模块和全局变量添加到上次建立的工程模块中。
把按钮中的代码改成:
sub command1_click()
With picture1
.ScaleMode=3
.BorderStyle=0
DibGet .hdc ,0 , 0 , .scalewidth , .scaleheight
ZoomImage , .scalewidth * 2 , .scaleheight * 2
End With
picture2.AutoRedraw=True
DibPut picture2.hdc
picture2.refresh
end sub
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