BMP to JPG (again)

  • Thread starter Thread starter Boris Nienke
  • Start date Start date
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Boris Nienke

Hi,

is there a function available (C# wrapper or something) to convert BMP file
to a JPG file?
i think i ask this once a year at least ;-) but i'm still hoping :)

thanks a lot

Boris
 
Hi,

is there a function available (C# wrapper or something) to convert BMP file
to a JPG file?
i think i ask this once a year at least ;-) but i'm still hoping :)
Click to expand...

Really no solution yet available?
Hard to believe....

Boris
 
yes - that's what i find whenever i start a new search about this topic.

But isn't there anyone who has done this allready?
A DLL or something with some wrapper-class to do this with C#?

I'm not a C/C++ guru - so writing a "wrapper around IJG" is not that easy
for me.

I'm still hoping that someone out there has done this successfully and like
to share <hope hope hope> :-)

Boris
 
Thanks a lot!
I will look deeper into it when i'm back home.

Currently i wonder what "SHLoadImageFile" exactly is/does and if it's
possible to do convertion to JPG with an in-memory bitmap. I will see

Boris
 
I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.

[1]
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/apippc/html/ppc_aygshell_thcu.asp
[2]
http://www.sergeybogdanov.com/Samples/JpegTest.zip

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
 
Cool, thank you!

Question:
---------
MSDN says about "SHLoadImageFile": [...]Converts a .gif file to a
bitmap.[...]
Now i know it also can load a BMP :-)

How did you know about this function(s) if you just knew, that you like to
load a BMP but didn' know if there's a MS-DLL available with some function
to do that?

And: my biggest problems with P/Invoke is, that i don't know which .Net
type/class is compatible to some C++ declaration/parameter in the
parameters. Is there something like a list or a documentation about this?

Boris

I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.

[1]
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/apippc/html/ppc_aygshell_thcu.asp
[2]
http://www.sergeybogdanov.com/Samples/JpegTest.zip

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com


Boris said:
Thanks a lot!
I will look deeper into it when i'm back home.

Currently i wonder what "SHLoadImageFile" exactly is/does and if it's
possible to do convertion to JPG with an in-memory bitmap. I will see

Boris
Click to expand...
Click to expand...
 
See below.

Boris said:
How did you know about this function(s) if you just knew, that you like to
load a BMP but didn' know if there's a MS-DLL available with some function
to do that?
Click to expand...
Have you tried to google:
http://groups-beta.google.com/group...owsce.embedded.vc&q=How+to+load+bitmap&qt_g=1
And: my biggest problems with P/Invoke is, that i don't know which .Net
type/class is compatible to some C++ declaration/parameter in the
parameters. Is there something like a list or a documentation about this?
Click to expand...

Types that have a common representation in unmanaged code and CF.NET
have name blittable types. Here you can find the more information about it:
http://msdn.microsoft.com/library/en-us/dnnetcomp/html/netcfintrointerp.asp


Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com
 
I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.
Click to expand...

It works great! THANKS A LOT!!!!!
Still havn't tried the in-memory way, but converting existing BMP files
ist really nice!

Boris
 
I have the same problem , i need convert a BMP into a JPG , i translate the
code of sergey , but a have several error and crash when convert the
images, any idea , any solution ,i'm desesperate.

Best Regards

Bmp_2_JPG_From_File("test.bmp","test.jpg")
Private Sub Bmp_2_JPG_From_File(ByVal cFicheroIn As String, ByVal
cFicheroOut As String)

Dim bmp As IntPtr = SHLoadImageFile(cFicheroIn)

ARM_WriteBitmapIntoJpegFile(cFicheroOut, 90, bmp)

End Sub

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function LoadLibrary(ByVal dllFile As String) As IntPtr

End Function

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function FreeLibrary(ByVal handle As IntPtr) As Boolean

End Function

<DllImport("aygshell.dll", EntryPoint:="#75", SetLastError:=True)> _

Public Shared Function SHLoadImageFile(ByVal szFileName As String) As IntPtr

End Function

<DllImport("coredll", SetLastError:=True)> _

Public Shared Function DeleteObject(ByVal hObject As IntPtr) As IntPtr

End Function

<DllImport("ARM_JpegLibThunk.dll", EnTryPoint:="WriteBitmapIntoJpegFile")> _

Private Function ARM_WriteBitmapIntoJpegFile(ByVal outFile As String, ByVal
quality As Integer, ByVal bitmap As IntPtr) As Boolean

End Function

<DllImport("ARM_JpegLibThunk.dll", EntryPoint:="WriteRGBBytesIntoJpegFile")>
_

Private Function ARM_WriteRGBBytesIntoJpegFile(ByVal outFile As String,
ByVal width As Integer, ByVal height As Integer, ByVal quality As Integer,
ByVal array As Byte) As Boolean

End Function





Boris Nienke said:
I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.
Click to expand...

It works great! THANKS A LOT!!!!!
Still havn't tried the in-memory way, but converting existing BMP files
ist really nice!

Boris
Click to expand...
 
Can you provide more information about what error you got?

Also I've noticed that you are calling ARM-compiled library. Did you try
to run it in emulator? If so, you have to replace it with X86 version
for emulator execution. See my example how I detect it at runtime.

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com


I have the same problem , i need convert a BMP into a JPG , i translate the
code of sergey , but a have several error and crash when convert the
images, any idea , any solution ,i'm desesperate.

Best Regards

Bmp_2_JPG_From_File("test.bmp","test.jpg")
Private Sub Bmp_2_JPG_From_File(ByVal cFicheroIn As String, ByVal
cFicheroOut As String)

Dim bmp As IntPtr = SHLoadImageFile(cFicheroIn)

ARM_WriteBitmapIntoJpegFile(cFicheroOut, 90, bmp)

End Sub

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function LoadLibrary(ByVal dllFile As String) As IntPtr

End Function

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function FreeLibrary(ByVal handle As IntPtr) As Boolean

End Function

<DllImport("aygshell.dll", EntryPoint:="#75", SetLastError:=True)> _

Public Shared Function SHLoadImageFile(ByVal szFileName As String) As IntPtr

End Function

<DllImport("coredll", SetLastError:=True)> _

Public Shared Function DeleteObject(ByVal hObject As IntPtr) As IntPtr

End Function

<DllImport("ARM_JpegLibThunk.dll", EnTryPoint:="WriteBitmapIntoJpegFile")> _

Private Function ARM_WriteBitmapIntoJpegFile(ByVal outFile As String, ByVal
quality As Integer, ByVal bitmap As IntPtr) As Boolean

End Function

<DllImport("ARM_JpegLibThunk.dll", EntryPoint:="WriteRGBBytesIntoJpegFile")>
_

Private Function ARM_WriteRGBBytesIntoJpegFile(ByVal outFile As String,
ByVal width As Integer, ByVal height As Integer, ByVal quality As Integer,
ByVal array As Byte) As Boolean

End Function





I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.
Click to expand...

It works great! THANKS A LOT!!!!!
Still havn't tried the in-memory way, but converting existing BMP files
ist really nice!

Boris
Click to expand...
Click to expand...
 
Thanks Sergey for your time ,

Best Regards





Sergey Bogdanov said:
Can you provide more information about what error you got?

Also I've noticed that you are calling ARM-compiled library. Did you try
to run it in emulator? If so, you have to replace it with X86 version
for emulator execution. See my example how I detect it at runtime.

Best regards,
Sergey Bogdanov
http://www.sergeybogdanov.com


I have the same problem , i need convert a BMP into a JPG , i translate the
code of sergey , but a have several error and crash when convert the
images, any idea , any solution ,i'm desesperate.

Best Regards

Bmp_2_JPG_From_File("test.bmp","test.jpg")
Private Sub Bmp_2_JPG_From_File(ByVal cFicheroIn As String, ByVal
cFicheroOut As String)

Dim bmp As IntPtr = SHLoadImageFile(cFicheroIn)

ARM_WriteBitmapIntoJpegFile(cFicheroOut, 90, bmp)

End Sub

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function LoadLibrary(ByVal dllFile As String) As IntPtr

End Function

<DllImport("coredll.dll", SetLastError:=True)> _

Private Shared Function FreeLibrary(ByVal handle As IntPtr) As Boolean

End Function

<DllImport("aygshell.dll", EntryPoint:="#75", SetLastError:=True)> _

Public Shared Function SHLoadImageFile(ByVal szFileName As String) As IntPtr

End Function

<DllImport("coredll", SetLastError:=True)> _

Public Shared Function DeleteObject(ByVal hObject As IntPtr) As IntPtr

End Function

<DllImport("ARM_JpegLibThunk.dll", EnTryPoint:="WriteBitmapIntoJpegFile")> _

Private Function ARM_WriteBitmapIntoJpegFile(ByVal outFile As String, ByVal
quality As Integer, ByVal bitmap As IntPtr) As Boolean

End Function

<DllImport("ARM_JpegLibThunk.dll", EntryPoint:="WriteRGBBytesIntoJpegFile")>
_

Private Function ARM_WriteRGBBytesIntoJpegFile(ByVal outFile As String,
ByVal width As Integer, ByVal height As Integer, ByVal quality As Integer,
ByVal array As Byte) As Boolean

End Function





On Wed, 27 Apr 2005 12:37:17 +0300, Sergey Bogdanov wrote:


I was using SHLoadImageFile [1] just for simplicity. It loads image file
and returns its HBITMAP which I pass to WriteBitmapIntoJpegFile.

To convert byte array with image into JPG file you have to use
WriteRGBBytesIntoJpegFile P/Invoke. The last parameter is an array with
length equals to height * width * 3 (where 3 bytes is RGB). I have
updated JpegTest [2] now it also demonstrates how to use
WriteRGBBytesIntoJpegFile function.

It works great! THANKS A LOT!!!!!
Still havn't tried the in-memory way, but converting existing BMP files
ist really nice!

Boris
Click to expand...
Click to expand...
Click to expand...
 
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