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Fastest way to load jpg images ?

Author
9 Mar 2006 2:20 PM
jordi_ramis@hotmail.com
Hi,
     I'm currently using image.fromfile to load jpg images in my
application. I've noted that this procedure is very slow compared to
some aplications I have seen. Is there any way to load a jpeg image
into an image or bitmap object faster that image.fromfile?. Prefereably
one method or component that is free.

     Thanks a lot for your help.

Author
9 Mar 2006 6:30 PM
Chris
jordi_ra***@hotmail.com wrote:
> Hi,
>      I'm currently using image.fromfile to load jpg images in my
> application. I've noted that this procedure is very slow compared to
> some aplications I have seen. Is there any way to load a jpeg image
> into an image or bitmap object faster that image.fromfile?. Prefereably
> one method or component that is free.
>
>      Thanks a lot for your help.
>

The question I have is if it is slow loading the image or is it slow
displaying the image (which is the part I believe would be slow for you)

Chris
Author
11 Mar 2006 4:54 AM
Robert
Show quote Hide quote
"Chris" <no@spam.com> wrote in message
news:OgOJae6QGHA.4344@TK2MSFTNGP12.phx.gbl...
> jordi_ra***@hotmail.com wrote:
>> Hi,
>>      I'm currently using image.fromfile to load jpg images in my
>> application. I've noted that this procedure is very slow compared to
>> some aplications I have seen. Is there any way to load a jpeg image
>> into an image or bitmap object faster that image.fromfile?. Prefereably
>> one method or component that is free.
>>
>>      Thanks a lot for your help.
>>
>
> The question I have is if it is slow loading the image or is it slow
> displaying the image (which is the part I believe would be slow for you)


I spent some time with this same issue last month.

98% of the time dealing with jpeg's is decompressing them. On my machine
with 1600x1200x24bpp I can load and display at about
15-32 images per second, depending on compression options.  Just displaying
from an array is over 200 per second.

So decode time is the killer.

Due to all the bit twiddling in decoding the images, I do not think that
..Net is the best choice.  3rd party C++ COM controls get about a 50% boost
over the .Net library image functions.

I saw a video on Channel 9 recently talking about a bunch of imaging speed
improvements in Vista.  Not much help at the moment..
Author
14 Mar 2006 3:52 PM
jordi_ramis@hotmail.com
Hi, thanks for your response. Can you tell me some 3rd party control to
speed up the jpeg load?. Thanks a lot.
Author
14 Mar 2006 3:51 PM
jordi_ramis@hotmail.com
I've tried to load the EXIF thumbnail instead of the jpeg itself and
I'm resizing the thumbnail to the image's original size, it is ver fast
so... THE PROBLEM IS LOADING/DECODING THE JPEG NOT SHOWING IT. That's,
obiously my opinion..