FreeImage中的透明度變得瘋狂

Question

在我的程序中，我想加載PNG或ICO文件（帶有透明度），然後將其另存爲具有透明度的ICO文件。

這是一個用於測試的隨機png圖片：

...正如你可以看到它富人的透明度。

但是當我嘗試將其轉換爲ICO這就是結果：

（從Windows資源管理器中採取圖片）

所有黑色丟失。

我試着用專業軟件做同樣的轉換，如photoshop，或者ToyCon和結果ICO文件沒有這個問題。

這是我的代碼，是我第一次使用FreeImage的，我不知道很多關於圖像和Alpha通道或透明度：

Imports FreeImageAPI 

'Dim img As FreeImageAPI.FIBITMAP = FreeImage.Load(format, file, FREE_IMAGE_LOAD_FLAGS.ICO_MAKEALPHA) 

Public Class Form1 

Dim file As String = "C:\Users\Administrador.ELEKTRO-PC\Desktop\auricular 5.png" 

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Shown 

    Dim format As FreeImageAPI.FREE_IMAGE_FORMAT = FreeImage.GetFileType(file, 32) 

    Dim img As FreeImageAPI.FIBITMAP = FreeImage.LoadEx(file) 

    Dim Transparency As Byte() = New Byte(0) {} 

    FreeImage.SetTransparencyTable(img, Transparency) 

    FreeImage.Save(FREE_IMAGE_FORMAT.FIF_ICO, img, "c:\test.ico", FREE_IMAGE_SAVE_FLAGS.DEFAULT) 

End Sub 

End Class 

Answer 1

完成。

我已經刪除了透明度表，似乎所有工作都很好，最後不需要設置透明度，我也做了一個新手幫助類來管理庫的一些基本功能（轉換圖像，旋轉，灰度，調整...）在一個簡單的方法：

#Region " FreeImage Helper " 

' [ FreeImage Helper ] 
' 
' // By Elektro H@cker 
' 
' 
' INSTRUCTIONS: 
' 1. ADD A REFERENCE FOR "FreeImageNET.dll" IN THE PROJECT. 
' 2. ADD THE "FREEIMAGE.DLL" IN THE PROJECT. 
' 
' 
' Examples : 
' 
' MsgBox(FreeImageHelper.Is_Avaliable() ' Result: True 
' MsgBox(FreeImageHelper.Get_Version() ' Result: 3.15.1 
' MsgBox(FreeImageHelper.Get_ImageFormat("C:\Test.png")) ' Result: PNG 
' 
' FreeImageHelper.Convert("C:\Test.png", "C:\Test.ico", FreeImageAPI.FREE_IMAGE_FORMAT.FIF_ICO) 
' FreeImageHelper.Convert(New Bitmap("C:\Test.png"), "C:\Test.jpg", FreeImageAPI.FREE_IMAGE_FORMAT.FIF_JPEG, FreeImageAPI.FREE_IMAGE_SAVE_FLAGS.JPEG_SUBSAMPLING_444 Or FreeImageAPI.FREE_IMAGE_SAVE_FLAGS.JPEG_QUALITYSUPERB) 
' 
' PictureBox1.BackgroundImage = FreeImageHelper.GrayScale(New Bitmap("C:\Test.bmp")) 
' PictureBox1.BackgroundImage = FreeImageHelper.GrayScale("C:\Test.bmp") 
' 
' PictureBox1.BackgroundImage = FreeImageHelper.Resize(New Bitmap("C:\Test.bmp"), 32, 32) 
' PictureBox1.BackgroundImage = FreeImageHelper.Resize("C:\Test.bmp", 64, 128) 
' 
' PictureBox1.BackgroundImage = FreeImageHelper.Rotate(New Bitmap("C:\Test.bmp"), 90) 
' PictureBox1.BackgroundImage = FreeImageHelper.Rotate("C:\Test.bmp", -90) 
' 
' PictureBox1.BackgroundImage = FreeImageHelper.Thumbnail(New Bitmap("C:\Test.png"), 64, True) 
' PictureBox1.BackgroundImage = FreeImageHelper.Thumbnail("C:\Test.png", 64, True) 



Imports FreeImageAPI 

Public Class FreeImageHelper 

' <summary> 
' Checks if <i>FreeImage.dll</i> is avaliable on the system. 
' </summary> 
Public Shared Function Is_Avaliable() As Boolean 
    Return FreeImage.IsAvailable 
End Function 

' <summary> 
' Gets the version of FreeImage.dll. 
' </summary> 
Shared Function Get_Version() As String 
    Return FreeImage.GetVersion 
End Function 

' <summary> 
' Gets the image format of a image file. 
' </summary> 
Shared Function Get_ImageFormat(ByVal File As String) As String 
    Return FreeImage.GetFileType(File, 0).ToString.Substring(4) 
End Function 

' <summary> 
' Convert a Bitmap object between image formats and save it to disk. 
' </summary> 
Shared Sub Convert(ByVal bmp As System.Drawing.Bitmap, _ 
        ByVal Output As String, _ 
        ByVal NewFormat As FREE_IMAGE_FORMAT, _ 
        Optional ByVal SaveFlags As FREE_IMAGE_SAVE_FLAGS = FREE_IMAGE_SAVE_FLAGS.DEFAULT) 

    Try 
     FreeImage.SaveBitmap(bmp, Output, NewFormat, SaveFlags) 
    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
    End Try 

End Sub 

' <summary> 
' Convert a image file between image formats and save it to disk. 
' </summary> 
Shared Sub Convert(ByVal File As String, _ 
        ByVal Output As String, _ 
        ByVal NewFormat As FREE_IMAGE_FORMAT, _ 
        Optional ByVal SaveFlags As FREE_IMAGE_SAVE_FLAGS = FREE_IMAGE_SAVE_FLAGS.DEFAULT) 

    Try 
     FreeImage.Save(NewFormat, FreeImage.LoadEx(File), Output, SaveFlags) 
    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
    End Try 

End Sub 

' <summary> 
' GrayScales a Bitmap object. 
' </summary> 
Shared Function GrayScale(ByVal bmp As System.Drawing.Bitmap) As System.Drawing.Bitmap 

    Try 

     Dim ImageStream As New System.IO.MemoryStream 
     bmp.Save(ImageStream, bmp.RawFormat) 

     Dim Image As FIBITMAP = FreeImage.LoadFromStream(ImageStream) 
     ImageStream.Dispose() 

     Return FreeImage.GetBitmap(FreeImage.ConvertToGreyscale(Image)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' GrayScales a image file. 
' </summary> 
Shared Function GrayScale(ByVal File As String) As System.Drawing.Bitmap 

    Try 
     Return FreeImage.GetBitmap(FreeImage.ConvertToGreyscale(FreeImage.LoadEx(File))) 
    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Resizes a Bitmap object. 
' </summary> 
Shared Function Resize(ByVal bmp As System.Drawing.Bitmap, _ 
         ByVal X As Int32, _ 
         ByVal Y As Int32, _ 
         Optional ByVal Quality As FREE_IMAGE_FILTER = FREE_IMAGE_FILTER.FILTER_BILINEAR) As System.Drawing.Bitmap 

    Try 

     Dim ImageStream As New System.IO.MemoryStream 
     bmp.Save(ImageStream, bmp.RawFormat) 

     Dim Image As FIBITMAP = FreeImage.LoadFromStream(ImageStream) 
     ImageStream.Dispose() 

     Return FreeImage.GetBitmap(FreeImage.Rescale(Image, X, Y, Quality)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Resizes a image file. 
' </summary> 
Shared Function Resize(ByVal File As String, _ 
         ByVal X As Int32, _ 
         ByVal Y As Int32, _ 
         Optional ByVal Quality As FREE_IMAGE_FILTER = FREE_IMAGE_FILTER.FILTER_BILINEAR) As System.Drawing.Bitmap 

    Try 

     Return FreeImage.GetBitmap(FreeImage.Rescale(FreeImage.LoadEx(File), X, Y, Quality)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Rotates a Bitmap object. 
' </summary> 
Shared Function Rotate(ByVal bmp As System.Drawing.Bitmap, _ 
         ByVal Angle As Double) As System.Drawing.Bitmap 

    Try 

     Dim ImageStream As New System.IO.MemoryStream 
     bmp.Save(ImageStream, bmp.RawFormat) 

     Dim Image As FIBITMAP = FreeImage.LoadFromStream(ImageStream) 
     ImageStream.Dispose() 

     Return FreeImage.GetBitmap(FreeImage.Rotate(Image, Angle)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Rotates a image file. 
' </summary> 
Shared Function Rotate(ByVal File As String, _ 
         ByVal Angle As Double) As System.Drawing.Bitmap 

    Try 

     Return FreeImage.GetBitmap(FreeImage.Rotate(FreeImage.LoadEx(File), Angle)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Returns a Thumbnail of a Bitmap object. 
' </summary> 
Shared Function Thumbnail(ByVal bmp As System.Drawing.Bitmap, _ 
           ByVal size As Int32, _ 
           ByVal convert As Boolean) As System.Drawing.Bitmap 

    Try 

     Dim ImageStream As New System.IO.MemoryStream 
     bmp.Save(ImageStream, bmp.RawFormat) 

     Dim Image As FIBITMAP = FreeImage.LoadFromStream(ImageStream) 
     ImageStream.Dispose() 

     Return FreeImage.GetBitmap(FreeImage.MakeThumbnail(Image, size, convert)) 

    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

' <summary> 
' Returns a Thumbnail of a image file. 
' </summary> 
Shared Function Thumbnail(ByVal File As String, _ 
           ByVal size As Int32, _ 
           ByVal convert As Boolean) As System.Drawing.Bitmap 

    Try 
     Return FreeImage.GetBitmap(FreeImage.MakeThumbnail(FreeImage.LoadEx(File), size, convert)) 
    Catch ex As Exception 
     ' Throw New Exception(ex.Message) 
     MsgBox(ex.Message) 
     Return Nothing 
    End Try 

End Function 

End Class 

#End Region