"Steve" <steve_mowbray@hotmail.com> wrote in message
news:LWete.52689$G8.14452@text.news.blueyonder.co.uk...
> Hi
>
> I am new to MSVS.NET and GDI and I am attempting to create a VC++ .NET
> Windows Forms App that will produce and display a bitmap.
>
> Using the default pixel format was pretty straightforward but really I
> would like the bitmap in colour indexed format for image processing use
> and would like to use Format8bppIndexed or perhaps later Format4bppIndexed
> formats.
>
> Trouble is SetPixel now causes an exception:
>
> "
> An unhandled exception of type 'System.Exception' occurred in
> system.drawing.dll
> Additional information: SetPixel is not supported for images with indexed
> pixel formats.
> "
>
> At least this is an informative error.
>
> I would be grateful if somebody could suggest a suitable alternative
> approach for GETting and SETting pixels in colour indexed pixel format
> bitmaps.
>
> Cheers
> Steve
>

"Garry Freemyer" <garryfre@pacbell.net.byespam> wrote in message
news:e%23MljXPdFHA.3040@TK2MSFTNGP14.phx.gbl...
> Perhaps you can copy it to another bitmap and change the format to
> unindexed along the way and then maybe
> you could change the format of the copy?
>

> "Steve" <steve_mowbray@hotmail.com> wrote in message
> news:LWete.52689$G8.14452@text.news.blueyonder.co.uk...
>> Hi
>>
>> I am new to MSVS.NET and GDI and I am attempting to create a VC++ .NET
>> Windows Forms App that will produce and display a bitmap.
>>
>> Using the default pixel format was pretty straightforward but really I
>> would like the bitmap in colour indexed format for image processing use
>> and would like to use Format8bppIndexed or perhaps later
>> Format4bppIndexed formats.
>>
>> Trouble is SetPixel now causes an exception:
>>
>> "
>> An unhandled exception of type 'System.Exception' occurred in
>> system.drawing.dll
>> Additional information: SetPixel is not supported for images with indexed
>> pixel formats.
>> "
>>
>> At least this is an informative error.
>>
>> I would be grateful if somebody could suggest a suitable alternative
>> approach for GETting and SETting pixels in colour indexed pixel format
>> bitmaps.
>>
>> Cheers
>> Steve
>>
>
>

"Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> wrote in message
news:e3wIuRQdFHA.3040@TK2MSFTNGP14.phx.gbl...
> The GDI+ FAQ has details of the LockBits method and it's usage.
>
> --
> Bob Powell [MVP]
> Visual C#, System.Drawing
>
> Find great Windows Forms articles in Windows Forms Tips and Tricks
> http://www.bobpowell.net/tipstricks.htm
>
> Answer those GDI+ questions with the GDI+ FAQ
> http://www.bobpowell.net/faqmain.htm
>
> All new articles provide code in C# and VB.NET.
> Subscribe to the RSS feeds provided and never miss a new article.
>
>
>
>
>
> "Steve" <steve_mowbray@hotmail.com> wrote in message
> news:LWete.52689$G8.14452@text.news.blueyonder.co.uk...
>> Hi
>>
>> I am new to MSVS.NET and GDI and I am attempting to create a VC++ .NET
>> Windows Forms App that will produce and display a bitmap.
>>
>> Using the default pixel format was pretty straightforward but really I
>> would like the bitmap in colour indexed format for image processing use
>> and would like to use Format8bppIndexed or perhaps later
>> Format4bppIndexed formats.
>>
>> Trouble is SetPixel now causes an exception:
>>
>> "
>> An unhandled exception of type 'System.Exception' occurred in
>> system.drawing.dll
>> Additional information: SetPixel is not supported for images with indexed
>> pixel formats.
>> "
>>
>> At least this is an informative error.
>>
>> I would be grateful if somebody could suggest a suitable alternative
>> approach for GETting and SETting pixels in colour indexed pixel format
>> bitmaps.
>>
>> Cheers
>> Steve
>>
>
>

"Steve" <steve_mowbray@hotmail.com> wrote in message
news:LWete.52689$G8.14452@text.news.blueyonder.co.uk...
> Hi
>
> I am new to MSVS.NET and GDI and I am attempting to create a VC++ .NET
> Windows Forms App that will produce and display a bitmap.
>
> Using the default pixel format was pretty straightforward but really I
> would like the bitmap in colour indexed format for image processing use
> and would like to use Format8bppIndexed or perhaps later Format4bppIndexed
> formats.
>
> Trouble is SetPixel now causes an exception:
>
> "
> An unhandled exception of type 'System.Exception' occurred in
> system.drawing.dll
> Additional information: SetPixel is not supported for images with indexed
> pixel formats.
> "
>
> At least this is an informative error.
>
> I would be grateful if somebody could suggest a suitable alternative
> approach for GETting and SETting pixels in colour indexed pixel format
> bitmaps.
>
> Cheers
> Steve
>

> unsigned char * pixel_buffer = (unsigned char *)
> pixMapData->Scan0.ToInt32();

"Etienne Boucher" <etienne@novat.qc.ca> wrote in message
news:uEM0JLedFHA.3012@tk2msftngp13.phx.gbl...
>> unsigned char * pixel_buffer = (unsigned char *)
>> pixMapData->Scan0.ToInt32();
>
> You might want to use byte*, remember that char is 16bit in .NET.

>
> Etienne Boucher
>