bmp轉png源碼
A. 急求把bmp壓縮成jpg的代碼，最好用.net寫的
給你一段代碼，支持很多格式之間的相互轉換：
從我的一個項目中截取出來的代碼段，你看其中代碼就可以了，控制項無所謂
private void button1_Click(object sender, EventArgs e)
{//瀏覽圖像文件
OpenFileDialog MyDlg = new OpenFileDialog();
MyDlg.Filter = "Image 圖像文件 (JPeg, Gif, Bmp, etc.)|*.jpg;*.jpeg;*.gif;*.bmp;*.tif; *.tiff; *.png| JPeg files (*.jpg;*.jpeg)| *.jpg;*.jpeg|GIF圖像文件(*.gif)|*.gif |BMP圖像文件(*.bmp)|*.bmp|Tiff圖像文件(*.tif;*.tiff)|*.tif;*.tiff|Png圖像文件(*.png)| *.png |所有文件(*.*)|*.*";
if (MyDlg.ShowDialog() == DialogResult.OK)
{
string MyFileName = MyDlg.FileName;
this.pictureBox1.Image = Image.FromFile(MyFileName);
}
}
private void button2_Click(object sender, EventArgs e)
{//轉換圖像文件
if (this.pictureBox1.Image == null)
{
MessageBox.Show("請首先選擇一幅圖像！", "信息提示",MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
SaveFileDialog MyDlg = new SaveFileDialog();
if (MyDlg.ShowDialog() == DialogResult.Cancel)
return;
string MyFileName = MyDlg.FileName;
try
{
if (this.radioButton1.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".bmp",System.Drawing.Imaging.ImageFormat.Bmp);
}
if (this.radioButton2.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".gif",System.Drawing.Imaging.ImageFormat.Gif);
}
if (this.radioButton3.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".jpg",System.Drawing.Imaging.ImageFormat.Jpeg);
}
if (this.radioButton4.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".png",System.Drawing.Imaging.ImageFormat.Png);
}
if (this.radioButton5.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".tif",System.Drawing.Imaging.ImageFormat.Tiff);
}
if (this.radioButton6.Checked)
{
this.pictureBox1.Image.Save(MyFileName + ".wmf",System.Drawing.Imaging.ImageFormat.Wmf);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "信息提示",MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
BMP是最簡單的圖形存儲格式，在c++里有朋友封裝了一個類CDib.
只要把圖片使用附件中編輯--粘貼來源找到圖畫打開另存為選擇你想要的格式保存就可以了。也可以右鍵點擊選擇打開方式使用圖畫打開相同的方法。另外photoshop 和office2003的picture manage也有這個功能。
Private Sub mnuconvertBMPtoJPG_Click()
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"
quality = 75
' Get info on the file we're to load
rcode = bmpinfo(bmp_fname, bdat)
If (rcode <> NO_ERROR) Then
MsgBox "Cannot find file", 0, "Error encountered!"
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 "Not enough memory", 0, "Error encountered!"
Exit Sub
End If
' Load image
rcode = loadbmp(bmp_fname, tmpimage)
If (rcode <> NO_ERROR) Then
freeimage tmpimage ' Free image on error
MsgBox "Cannot load file", 0, "Error encountered!"
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
imgdes tmp2image, tmpimage
End If
End If
' Save image
rcode = savejpg(jpg_fname, tmpimage, quality)
freeimage tmpimage
End Sub
........... Add these defines and declarations to your Global mole ...........
' 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
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 imgdes 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
《圖像處理----做一個自己的photoshop》
大部分都是源碼，其中有bmp<-->jgep<-->GIF的代碼.