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transparent colours for images

I'm trying to make the background of a picture transparent, so I use
paint to fill the background with blue (0,0,255), then set the
transparent colour to it. I found a custom control that can do the
job.

Now the problem is the paint program can't seem to save the file with
the exact colour i need. every time I open the picture file again , I
see the blue background has a range of colours (<30,<30,>230)

I tried in Java and I was able to set a range of colours transparent.
How do I do it with vb.net?
I will need to have the image in the picturebox control at the end.

Feb 6 '07 #1
2 2416
On Feb 6, 6:29 am, "wanwan" <ericwa...@yaho o.comwrote:
I'm trying to make the background of a picture transparent, so I use
paint to fill the background with blue (0,0,255), then set the
transparent colour to it. I found a custom control that can do the
job.

Now the problem is the paint program can't seem to save the file with
the exact colour i need. every time I open the picture file again , I
see the blue background has a range of colours (<30,<30,>230)

I tried in Java and I was able to set a range of colours transparent.
How do I do it with vb.net?
I will need to have the image in the picturebox control at the end.
If you are saving the image as a JPG you may lose the EXACT colour you
want to use. I think png image format is much better for this sort of
thing. TIFF images would also work but would be quite large.

Feb 6 '07 #2
Also, the .jpg graphic format doesn't support transparency. Another format
that would is the .gif format, but it can really make a good looking graphic
look awful if you aren't careful in how you create it.

Bruce

<lo*********@gm ail.comwrote in message
news:11******** **************@ m58g2000cwm.goo glegroups.com.. .
On Feb 6, 6:29 am, "wanwan" <ericwa...@yaho o.comwrote:
>I'm trying to make the background of a picture transparent, so I use
paint to fill the background with blue (0,0,255), then set the
transparent colour to it. I found a custom control that can do the
job.

Now the problem is the paint program can't seem to save the file with
the exact colour i need. every time I open the picture file again , I
see the blue background has a range of colours (<30,<30,>230)

I tried in Java and I was able to set a range of colours transparent.
How do I do it with vb.net?
I will need to have the image in the picturebox control at the end.

If you are saving the image as a JPG you may lose the EXACT colour you
want to use. I think png image format is much better for this sort of
thing. TIFF images would also work but would be quite large.

Feb 10 '07 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

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