Problem with indexed pixel format/

[jty202]

I know alot of people have the problem with indexed pixel format. I hope
someone can show me the solution to this.I am have problem with graphics
with the following code giving the error:

"A Graphics object cannot be created from an image that has an indexed pixel
format."

'My code


<%@ Page Language="vb" %>
<%@ import namespace="syst em.drawing" %>
<%@ import namespace="syst em.drawing.imag ing" %>
<%@ import namespace="syst em.drawing.draw ing2d" %>


<%

' initialise the web object
Dim webC As New System.Net.WebC lient()

' set the URL
Dim strFilename as string


strFilename="ht tp://www.domain.com/graph.gif"

' create a bitmap based on the image from the URL
Dim g = New System.Drawing. Bitmap(webC.Ope nRead(strFilena me))


response.conten ttype="image/gif"

dim gr as graphics = graphics.fromim age(g) ' create a New graphic object
from the above bmp

gr.smoothingMod e = smoothingMode.a ntiAlias ' antialias objects

'' draw the number on the image canvas in verdana 10pt font bold
gr.drawString(" ABC", New
font("verdana", 14,fontstyle.bo ld),systembrush es.windowtext, New pointF(2,2))


' send the image to the viewer
g.save(response .outputstream, g.rawformat)

' tidy up
g.dispose()
gr.dispose()
webC = Nothing

%>

[Bob Powell [MVP]]

Re: Problem with indexed pixel format/

This is intended behaviour. The error "A Graphics object cannot be created
from an image that has an indexed pixel format." says it all.

You need to create an image the same size as the original, get the Graphics
object for it, draw the original onto the new Graphics object, draw your
number and then save the newly created bitmap to the response stream.

--
Bob Powell [MVP]
Visual C#, System.Drawing

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"jty202" <jty202@gmail.c om> wrote in message
news:e13tjuZAFH A.3700@tk2msftn gp13.phx.gbl...[color=blue]
>I know alot of people have the problem with indexed pixel format. I hope
> someone can show me the solution to this.I am have problem with graphics
> with the following code giving the error:
>
> "A Graphics object cannot be created from an image that has an indexed
> pixel
> format."
>
> 'My code
>
>
> <%@ Page Language="vb" %>
> <%@ import namespace="syst em.drawing" %>
> <%@ import namespace="syst em.drawing.imag ing" %>
> <%@ import namespace="syst em.drawing.draw ing2d" %>
>
>
> <%
>
> ' initialise the web object
> Dim webC As New System.Net.WebC lient()
>
> ' set the URL
> Dim strFilename as string
>
>
> strFilename="ht tp://www.domain.com/graph.gif"
>
> ' create a bitmap based on the image from the URL
> Dim g = New System.Drawing. Bitmap(webC.Ope nRead(strFilena me))
>
>
> response.conten ttype="image/gif"
>
> dim gr as graphics = graphics.fromim age(g) ' create a New graphic object
> from the above bmp
>
> gr.smoothingMod e = smoothingMode.a ntiAlias ' antialias objects
>
> '' draw the number on the image canvas in verdana 10pt font bold
> gr.drawString(" ABC", New
> font("verdana", 14,fontstyle.bo ld),systembrush es.windowtext, New
> pointF(2,2))
>
>
> ' send the image to the viewer
> g.save(response .outputstream, g.rawformat)
>
> ' tidy up
> g.dispose()
> gr.dispose()
> webC = Nothing
>
> %>
>
>
>[/color]