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I'm having problems with quality of JPEG's in D5

I've tried using TImageEn components and I've tried the native support for
the jpeg images and it seems when tring to reduce the image size I loose
quality. If I try and use a off the shelf program like Paint Shop pro I
dont loose the quality when I shrink the resolution of the image. ie width
400 height 600 new width 100 new height 150 but it seems when I use these
components to do it I loose image quality.. does anyone know why ?
 

Re:I'm having problems with quality of JPEG's in D5


maybe you are referring to the image losing some pixels? and getting sharp
edges where there should not
be and flat spots where there should be rounded corners ?
 is this the problem you are seeing ?
 if soo then the components you are using  are are just using the simple video
GDI stretchDraw..
Quote
Aaron wrote:
> I've tried using TImageEn components and I've tried the native support for
> the jpeg images and it seems when tring to reduce the image size I loose
> quality. If I try and use a off the shelf program like Paint Shop pro I
> dont loose the quality when I shrink the resolution of the image. ie width
> 400 height 600 new width 100 new height 150 but it seems when I use these
> components to do it I loose image quality.. does anyone know why ?

Re:I'm having problems with quality of JPEG's in D5


Quote
"Aaron " <aar...@bit.net.au> wrote:
>I've tried using TImageEn components and I've tried the native support for
>the jpeg images and it seems when tring to reduce the image size I loose
>quality. If I try and use a off the shelf program like Paint Shop pro I
>dont loose the quality when I shrink the resolution of the image. ie width
>400 height 600 new width 100 new height 150 but it seems when I use these
>components to do it I loose image quality.. does anyone know why ?

Maybe a stupid question, but have you set the JPEG to 'best quality'
(as opposed to 'best performance'?

Something like this:

          with TJPEGImage(form1.Image1.Picture.Graphic) do
          begin
            performance := jpbestquality;
            grayscale := false;
            pixelformat := jf8bit;
          end;

Steve

Steve Gouldstone

Helpburger: easy to use and affordable Windows Help
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Re:I'm having problems with quality of JPEG's in D5


Quote
>I've tried using TImageEn components and I've tried the native support for
>the jpeg images and it seems when tring to reduce the image size I loose
>quality. If I try and use a off the shelf program like Paint Shop pro I
>dont loose the quality when I shrink the resolution of the image.

I don't know anything about the TImageEn component, but perhaps it is using
a different scaling algorithm than your paint program.  Also, if you are
doing several manipulations on the images, decompress the image, do all of
the manipulations on the uncompressed image, and recompress at the end.

Regards,

Wayne

Re:I'm having problems with quality of JPEG's in D5


I think with PaintShop you use "resample" instead of "resize"?
With standard Delphi-components you just can do a resize (without
sub/super-sampling/antialiasign etc.).
There are 3rd-Party-components out there which do an antialiasing when
scaling... anybody knows an URL??

cu

Boris

Quote
Aaron <aar...@bit.net.au> wrote in message

news:01bf1f9e$3b30a200$5b96a8c0@server...
Quote
> I've tried using TImageEn components and I've tried the native support for
> the jpeg images and it seems when tring to reduce the image size I loose
> quality. If I try and use a off the shelf program like Paint Shop pro I
> dont loose the quality when I shrink the resolution of the image. ie width
> 400 height 600 new width 100 new height 150 but it seems when I use these
> components to do it I loose image quality.. does anyone know why ?

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