в 16:40, 26 мая 2010

2010-05-26T16:40:30Z

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2010-05-26T12:55:10Z

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==Create Jpeg File==

<source lang="vbnet">Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Imaging
public class MainClass
public Shared Sub Main
Dim bm As New Bitmap(256, 256)
Dim gr As Graphics = Graphics.FromImage(bm)
gr.Clear(Color.White)
gr.DrawEllipse(Pens.Red, 0, 0, bm.Width - 1, bm.Height - 1)
gr.DrawLine(Pens.Green, 0, 0, bm.Width - 1, bm.Height - 1)
gr.DrawLine(Pens.Blue, bm.Width - 1, 0, 0, bm.Height - 1)
" Save the result as a JPEG file.

bm.Save("test.jpg", ImageFormat.Jpeg)
End Sub
End class</source>

==Get Jpeg Information==

<source lang="vbnet">" Quote from
"Visual Basic 2005 Cookbook Solutions for VB 2005 Programmers
"by Tim Patrick (Author), John Craig (Author)
"# Publisher: O"Reilly Media, Inc. (September 21, 2006)
"# Language: English
"# ISBN-10: 0596101775
"# ISBN-13: 978-0596101770

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Public Class GetJpgInformation
Public Shared Sub Main
Console.WriteLine(ProcessJPEG.GetJpgInformation("yourfile.jpg"))
End Sub
End Class

Public Class ProcessJPEG
Public Shared Function GetJpgInformation(ByVal whichFile As String) As String
Dim bytesPropertyID As Byte()
Dim stringPropertyID As String
Dim loadedImage As System.Drawing.Bitmap
Dim propertyIDs() As Integer
Dim result As New System.Text.StringBuilder
Dim counter As Integer
Dim scanProperty As Integer
loadedImage = New System.Drawing.Bitmap(whichFile)
propertyIDs = loadedImage.PropertyIdList
For Each scanProperty In propertyIDs
bytesPropertyID = loadedImage.GetPropertyItem(scanProperty).Value
stringPropertyID = System.Text.Encoding.ASCII.GetString(bytesPropertyID)
For counter = 0 To 255
If counter < 32 Or counter > 127 Then
If (stringPropertyID.IndexOf(Chr(counter)) _
<> -1) Then
stringPropertyID = Replace(stringPropertyID, _
Chr(counter), "")
End If
End If
Next counter
" ----- Display the property if it"s reasonable.
If (stringPropertyID.Length > 0) And _
(stringPropertyID.Length < 70) Then
result.Append(scanProperty.ToString)
result.Append(": ")
result.AppendLine(stringPropertyID)
End If
Next scanProperty
" ----- Display the results.
Return result.ToString
End Function
Public Shared Function GetString( _
ByVal sourceBytes As Byte()) As String
" ----- Convert a byte array to a string, taking into
" account the terminating null character.
Dim result As String
result = System.Text.Encoding.ASCII.GetString(sourceBytes)
If (result.EndsWith(vbNullChar) = True) Then _
result = result.Substring(0, result.Length - 1)
Return result
End Function
End Class</source>

==JPEG Compression==

<source lang="vbnet">Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Data
Imports System.Drawing.Imaging
public class MainClass
public Shared Sub Main
Dim curBitmap As Bitmap
Dim imgCodecInfo As ImageCodecInfo = Nothing
Dim encoder As Encoder
Dim encoderParam As EncoderParameter
Dim encoderParams As New EncoderParameters(1)
curBitmap = New Bitmap("yourfile.jpg")
Dim j As Integer
Dim mimeType As String = "image/jpeg"
Dim encoders() As ImageCodecInfo
encoders = ImageCodecInfo.GetImageEncoders()
j = 0
While j < encoders.Length
If encoders(j).MimeType = mimeType Then
imgCodecInfo = encoders(j)
End If
End While "
encoder = encoder.rupression
encoderParam = New EncoderParameter(encoder, 1, CInt(EncoderParameterValueType.ValueTypeLong), 0)
encoderParams.Param(0) = encoderParam "
curBitmap.Save("Shape0.jpg", imgCodecInfo, encoderParams)
End Sub
End class</source>

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VB.Net Tutorial/2D Graphics/Jpeg - История изменений

в 16:40, 26 мая 2010

Admin: 1 версия