JPG compression

Hi,

I have a question about the JPG compression in CF2.0

I tested to load a jpg-image of about 2Mb into a bitmap, and the then
save it at once. The saved image is of only 600kB.

bmpMap = new Bitmap("Test.jpg");
bmpMap.Save"Test.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);

Is there a fixed compression rate when saving to JPG, or can it be
adjusted?

/Broeden

ctacke/>
Tue Jan 29 07:53:41 CST 2008

It's not adjustable.


--

Chris Tacke, eMVP
Join the Embedded Developer Community
http://community.opennetcf.com


"Broeden" <hihansson@hotmail.com> wrote in message
news:034225d1-6f06-4e75-a884-4e260bff7389@s12g2000prg.googlegroups.com...
> Hi,
>
> I have a question about the JPG compression in CF2.0
>
> I tested to load a jpg-image of about 2Mb into a bitmap, and the then
> save it at once. The saved image is of only 600kB.
>
> bmpMap = new Bitmap("Test.jpg");
> bmpMap.Save"Test.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
>
> Is there a fixed compression rate when saving to JPG, or can it be
> adjusted?
>
> /Broeden

Broeden
Tue Jan 29 08:33:13 CST 2008

On 29 Jan, 14:53, "<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote:
> It's not adjustable.

Is this fixed compression ratio documented someware?

/Broeden

ctacke/>
Tue Jan 29 08:47:15 CST 2008

there isn't a "fixed ratio". The compression rate depends on the source
data, just like with most compression algorithms. If you want a better
compression rate, try a couple other formats. FOr example, if the images
have large blocks of the same color (like a screen shot) then GIF is far
better than JPG for compression.


--

Chris Tacke, eMVP
Join the Embedded Developer Community
http://community.opennetcf.com


"Broeden" <hihansson@hotmail.com> wrote in message
news:d319e5d1-c202-4ff4-b638-d94cad2391fb@v67g2000hse.googlegroups.com...
> On 29 Jan, 14:53, "<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote:
>> It's not adjustable.
>
> Is this fixed compression ratio documented someware?
>
> /Broeden

Broeden
Tue Jan 29 10:12:16 CST 2008

On 29 Jan, 15:47, "<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote:
> there isn't a "fixed ratio". The compression rate depends on the source
> data, just like with most compression algorithms. If you want a better
> compression rate, try a couple other formats. FOr example, if the images
> have large blocks of the same color (like a screen shot) then GIF is far
> better than JPG for compression.
>

I thought there might be a compression ratio adjustment like in many
picture editing software's

see http://www.mdash.net/examples/jpeg_gif.php

/Broeden

ctacke/>
Tue Jan 29 12:42:03 CST 2008

Nope, the CF has no way to adjust the ratio.


--

Chris Tacke, eMVP
Join the Embedded Developer Community
http://community.opennetcf.com


"Broeden" <hihansson@hotmail.com> wrote in message
news:904afaa3-1a43-4cb1-82a2-488db0bf133c@l32g2000hse.googlegroups.com...
> On 29 Jan, 15:47, "<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote:
>> there isn't a "fixed ratio". The compression rate depends on the source
>> data, just like with most compression algorithms. If you want a better
>> compression rate, try a couple other formats. FOr example, if the images
>> have large blocks of the same color (like a screen shot) then GIF is far
>> better than JPG for compression.
>>
>
> I thought there might be a compression ratio adjustment like in many
> picture editing software's
>
> see http://www.mdash.net/examples/jpeg_gif.php
>
> /Broeden