JPG compression

Broeden · Joined: 08 Aug 2007 Posts: 13

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

Archived from group: microsoft>public>dotnet>framework>compactframework

user · Joined: 08 Aug 2007 Posts: 286

It's not adjustable.

--

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

"Broeden" wrote in message @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 · Joined: 08 Aug 2007 Posts: 13

On 29 Jan, 14:53, "" wrote:
> It's not adjustable.

Is this fixed compression ratio documented someware?

/Broeden

user · Joined: 08 Aug 2007 Posts: 286

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" wrote in message @v67g2000hse.googlegroups.com...
> On 29 Jan, 14:53, "" wrote:
>> It's not adjustable.
>
> Is this fixed compression ratio documented someware?
>
> /Broeden

Broeden · Joined: 08 Aug 2007 Posts: 13

On 29 Jan, 15:47, "" 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

user · Joined: 08 Aug 2007 Posts: 286

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

--

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

"Broeden" wrote in message @l32g2000hse.googlegroups.com...
> On 29 Jan, 15:47, "" 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

Compression Before Encryption? Hi! I'm using the 128 bit class in C# to encrypt several kilobytes (30-100 KB) of uncompressed text data. The question I have is: Would it generally make any sense (i.e. performance gain) to compress the text data before I encrypt it and v

Image Compression I am working on an application that deals with multi-page Tiffs. I have a function that given a page will added to the existing M-Tiff. However, I am creating 16MB files for an image with only two frames. I have been using the encoder va

.NET CLR exception when using compression sink Using Ingo Rammer's "Extended .NET Remoting" as my basis, I've added a client-side compression sink after my and a server-side compression sink before my The compression / decompression routines each r

Determining BALLPARK Memory Consumption for Instantiated Obj First of all I realize if I am able to get anything, its not going to be 100% right on. What I'd like to do is get ballpark idea of a instantiated objects memory consumption. I am writing a specialized managed cache, that needs to start attempting to purg

ThreadContext, ThreadException and message loop(pump) From a previous posting, I learnt that the Application class's Run method starts a message loop(pump) on the current thread. But the following findings confuse me. 1. When I look at the message loop code using the .NET reflector, I see a lot of code refer