bitmap转换后，新的bitmap图像宽度变成了原来的2倍怎么回事
bitmap转换后，新的bitmap图像宽度变成了原来的2倍怎么回事
函数如下。
输入一个bitmap,输出一个bitmap，把第二个bitmap Save到文件里，发现文件宽度像素没有变，但是内容被宽度拉伸了2倍，所以只显示了原来内容的左半部分，原来的右半部分溢出没有了，高度都是正好的，没有变，原内容的全部高度的内容都被显示出来了。
Private Function get1bppBmp(ByVal dpiX As Integer, ByVal dpiY As Integer, ByVal tmpbm As System.Drawing.Bitmap) As System.Drawing.Bitmap
Dim H As Integer
Dim W As Integer
Dim img As System.Drawing.Bitmap
img = CType(tmpbm.Clone(), System.Drawing.Bitmap)
W = img.Width
H = img.Height
Dim bd_img As System.Drawing.Imaging.BitmapData
bd_img = img.LockBits(New System.Drawing.Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadOnly, img.PixelFormat)
Dim baseBm As New System.Drawing.Bitmap(img.Width, img.Height, PixelFormat.Format1bppIndexed)
baseBm.SetResolution(dpiX, dpiY)
Dim bd_basebm As System.Drawing.Imaging.BitmapData
bd_basebm = baseBm.LockBits(New System.Drawing.Rectangle(0, 0, baseBm.Width, baseBm.Height), ImageLockMode.ReadWrite, PixelFormat.Format1bppIndexed)
MsgBox("Basebm.with=")
MsgBox(baseBm.Width)
Dim X, Y, n As Int32
Dim b As Byte
For Y = 0 To H - 1
n = bd_basebm.Stride * Y
For X = 0 To W - 1
If GetPixel4dpp1(X, Y, bd_img) Then
b += CType(2 ^ (7 - X Mod 8), Byte)
End If
If (X + 1) Mod 8 = 0 Then
System.Runtime.InteropServices.Marshal.WriteByte(bd_basebm.Scan0, n, b)
n += 1
b = 0
End If
Next
If W Mod 8 > 0 Then
System.Runtime.InteropServices.Marshal.WriteByte(bd_basebm.Scan0, n, b)
b = 0
End If
Next
img.UnlockBits(bd_img)
baseBm.UnlockBits(bd_basebm)
Return baseBm
End Function
Function GetPixel4dpp1(ByVal X As Int32, ByVal Y As Int32, ByVal Img2_Da As System.Drawing.Imaging.BitmapData) As Boolean
Dim ofs As Int32 = Y * Img2_Da.Stride + X * 3
Dim R, G, B As Byte
R = System.Runtime.InteropServices.Marshal.ReadByte(Img2_Da.Scan0, ofs + 2)
G = System.Runtime.InteropServices.Marshal.ReadByte(Img2_Da.Scan0, ofs + 1)
B = System.Runtime.InteropServices.Marshal.ReadByte(Img2_Da.Scan0, ofs)
Dim yy As Byte = CType(R * 0.3 + G * 0.59 + B * 0.11, Byte)
If yy < 255 Then
Return False
Else
Return True
End If
End Function
[解决办法]
我想知道
img = CType(tmpbm.Clone(), System.Drawing.Bitmap)
中tmpbm是什么控件,然后显示模式是什么比如zoom,显示的图像大小多大.
[解决办法]
baseBm.SetResolution(dpiX, dpiY)
这里开始被缩放分辨率了.
[解决办法]
