save bitmap to jpg quality loss

[Peter Proost]

Hi group I've got a bitmap with a white background in a picturebox and I do
some drawing on this bitmap but when I save the bitmap as .jpg there's some
quality loss, nothing you can see if you just open the picture. But if you
zoom in on it there are some lightgray pixels that should be white
(background color) , can I do something about this or do I just have to live
with it, that it's part of converting from bitmap to jpg

Grtz Peter

 

[Cor Ligthert]

Peter,

There will be almost forever quality loss when you use a compressed format.

That is why they changing it all the time and improve it.
(And Tiff is so huge)

Cor

 

[Peter Proost]

That's what I thought, that I just have to live with it. But it isn't a big
problem, because it aren't very large images so the user can save them as
bmp. The problem with the gray pixels was that if they edit the picture in
paint for example and use the paint bucket it stops at a gray pixel. But
that realy isn't my problem, because my program hands the user a drawing and
if they want to edit it externaly it's their responsibility.

Thnx for your time Cor

 

[Herfried K. Wagner [MVP]]

Peter,

Hi group I've got a bitmap with a white background in a picturebox and I do
some drawing on this bitmap but when I save the bitmap as .jpg there's some
quality loss, nothing you can see if you just open the picture. But if you
zoom in on it there are some lightgray pixels that should be white
(background color) , can I do something about this or do I just have to live
with it, that it's part of converting from bitmap to jpg

That's due to JPEG compression. You can adjust the compression level to
minimize these artifacts:

<URL:http://groups.google.de/groups?selm=uvfKr3xSCHA.1960@tkmsftngp09>

I suggest to use another image format, like PNG or GIF instead.

 

[Peter Proost]

Hi Herfried,

Thnx for the link, I'll check it out

Grtz Peter