在我的程序中,我想加载一个PNG或ICO文件(带透明度),然后将其保存为具有透明度的ICO文件。
这是一个用于测试的随机png图像:
......你可以看到它具有透明度。
但是当我尝试将其转换为ICO时,结果如下:
(从Windows资源管理器拍摄的照片)
所有黑色都丢失了。
我尝试使用专业软件进行相同的转换,如photoshop或ToyCon,结果ICO文件没有此问题。
这是我的代码,这是我第一次使用FreeImage而且我对图像和alpha通道或透明度了解不多:
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
答案 0 :(得分:0)
完成。
我删除了透明表,似乎一切正常,最后不需要设置透明度,我也做了一个新手助手类来管理库的一些基本功能(转换图像,旋转,灰度,调整大小......)以一种简单的方式:
#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