If you have GD2 I'd advise using imagecopyresampled, as I found using
imagecopyresized often resulted in blue or grayish images, while
imagecopyresampled resulted in normal looking images.
Jason Reid
[EMAIL PROTECTED]
--
AC Host Canada
www.achost.ca
----- Original Message -----
From: "Dave at Sinewaves.net" <[EMAIL PROTECTED]>
To: "Arcadius A." <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Sunday, August 25, 2002 12:23 PM
Subject: RE: [PHP] GD lib. image quality!
> imageCreate will create an image, but its palette will be very limited, so
> when you try to copy your photo onto it, it will maintain the palette of
the
> original picture. Obviously, this is not what you want, since the picture
> comes out looking all grey and faded (probably 8-16 colors!).
>
> What works for me is creating a blank image using imageCreate(), then
saving
> it as a temporary jpeg (using imageJpeg). This action will set the palette
> of the image to a jpeg's palette (close to 16-bit or better colorspace).
If
> you imageCopyResized over this temp.jpg (which you need to create whenever
> you run the script to ensure sizing is perfect), it will come out with the
> full palette of colors.
>
> Pseudo code:
> <?
> $dest_h = whatever your calculated destination height is;
> $dest_w = whatever your calculated destination width is;
>
> $src_h = height of original image;
> $src_w = width of original image;
>
> // create the blank limited-palette image
> $base_image = imageCreate($dest_w, $dest_h);
>
> // convert and save it to temp.jpg
> imagejpeg($base_image, 'path/to/temp.jpg');
>
> // get the image pointer to the temp jpeg
> $image = imageCreateFromJpeg('path/to/temp.jpg');
>
> // get the image pointer to the original image
> $imageToResize = imageCreateFromJpeg('path/to/image_to_be_resized.jpg');
>
> // resize the original image over temp.jpg
> // since you have GD2, you could also use imageCopyResampled
> imageCopyResized($image, $imageToResize, 0, 0, 0, 0, $dest_w, $dest_h,
> $src_w, $src_h);
>
> // values for output jpeg quality
> $jpegQuality = 75;
>
> // create the resized image
> imageJpeg($image, 'path/to/thumbnail_name.jpg', $jpegQuality);
> ?>
>
>
> Then all you have to do is a little cleanup with imageDestroy() and you
> should have a nice looking thumbnail!
>
>
> I usually add a line like this to the script to make sure everything went
> smoothly:
> <?
> echo '<html><head><title>Thumbnail Generator</title>'
> .'</head><body><img src="path/to/thumbnail_name.jpg">'
> .'</body></html>';
> ?>
>
> It lets me see the quality of the thumbnail the second the script
completes.
>
>
> Try it - you'll get perfect thumbnails every time. I used this technique
> for all of the pictures at www.arkestraclandestina.com with GD1.6 - and
all
> of them actually had custom color profiles! Works like a charm.
>
> I like this method because I can be sure that the script won't break on
> sites with older PHP and GD versions - which is an important consideration
> when you're deploying applications to other sites...
>
> However! If you are sure it will only be run on a PHP4, GD2 system, you
can
> avoid all of the temp jpg madness altogether by just altering your code to
> use imageCreateTrueColor() instead of imageCreate()!! ;P Easy as pie!
>
> Dave
>
>
>
> -----Original Message-----
> From: Arcadius A. [mailto:[EMAIL PROTECTED]]
> Sent: Sunday, August 25, 2002 4:11 AM
> To: [EMAIL PROTECTED]
> Subject: [PHP] GD lib. image quality!
>
>
> Hello!
> I wrote a little script for generation thumbnails of larger images....
> <code>
> $origImage = imageCreateFromJpeg($sourcePath."/".$currentImageName);
> $thumbnail = imageCreate($thumbWidth,$thumbHeight);// create empty
image
>
>
imageCopyResized($thumbnail,$origImage,0,0,0,0,$thumbWidth,$thumbHeight,imag
> esX($origImage),imagesY($origImage));
> imageJpeg($thumbnail, $targetPath."/".$thumbNamePrefix."_thumb.jpg");
//
> Store it
> imageDestroy($thumbnail); // cleanup
> echo "<br>Image ".$targetPath."/".$thumbNamePrefix."_thumb.jpg"."
> created successfully!";
>
> </code>
>
> then, I've noticed that the quality of the thumbnails created is very bad!
> my "phpinfo()" page shows "2.0 or higher" as GD version
>
> So, I'm wondering whether I'm doing something wrong in my code or whether
> there exist a better library to use with PHP ... a library able to
generate
> good quality JPG files...
>
> Thanks in advance.
>
> Arcadius.
>
>
>
>
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