resized image quality sucks

[aebstract]

 

Is there a way to make the image quality better after resize? Here is the script I am using:

 

$idir = "gallery/$_POST[category]/";   // Path To Images Directory
$tdir = "gallery/$_POST[category]/thumbs/";   // Path To Thumbnails Directory
$twidth = "200";   // Maximum Width For Thumbnail Images
$theight = "900";   // Maximum Height For Thumbnail Images

// Uploading/Resizing Script
  $url = $_FILES['imagefile']['name'];   // Set $url To Equal The Filename For Later Use
  if ($_FILES['imagefile']['type'] == "image/jpg" || $_FILES['imagefile']['type'] == "image/jpeg" || $_FILES['imagefile']['type'] == "image/pjpeg") {
    $file_ext = strrchr($_FILES['imagefile']['name'], '.');   // Get The File Extention In The Format Of , For Instance, .jpg, .gif or .php
    $copy = copy($_FILES['imagefile']['tmp_name'], "$idir" . $_FILES['imagefile']['name']);   // Move Image From Temporary Location To Permanent Location
    if ($copy) {   // If The Script Was Able To Copy The Image To It's Permanent Location
      print 'Image uploaded successfully.<br />';   // Was Able To Successfully Upload Image
      $simg = imagecreatefromjpeg("$idir" . $url);   // Make A New Temporary Image To Create The Thumbanil From
      $currwidth = imagesx($simg);   // Current Image Width
      $currheight = imagesy($simg);   // Current Image Height


    if ($currheight > $currwidth) {   // If Height Is Greater Than Width
        $zoom = $twidth / $currwidth;   // Length Ratio For Height
        $newwidth = $twidth;   // Width Is Equal To Max Width
        $newheight = $currheight * $zoom;   // Creates The New Height
      } else {    // Otherwise, Assume Width Is Greater Than Height (Will Produce Same Result If Width Is Equal To Height)
        $zoom = $twidth / $currwidth;   // Length Ratio For Height
        $newwidth = $twidth;   // Width Is Equal To Max Width
        $newheight = $currheight * $zoom;   // Creates The New Height
      }




    $dimg = imagecreate($newwidth, $newheight);   // Make New Image For Thumbnail
      imagetruecolortopalette($simg, false, 256);   // Create New Color Pallete
      $palsize = ImageColorsTotal($simg);
      for ($i = 0; $i < $palsize; $i++) {   // Counting Colors In The Image
       $colors = ImageColorsForIndex($simg, $i);   // Number Of Colors Used
       ImageColorAllocate($dimg, $colors['red'], $colors['green'], $colors['blue']);   // Tell The Server What Colors This Image Will Use
      }
      imagecopyresized($dimg, $simg, 0, 0, 0, 0, $newwidth, $newheight, $currwidth, $currheight);   // Copy Resized Image To The New Image (So We Can Save It)
      imagejpeg($dimg, "$tdir" . $url);   // Saving The Image
      imagedestroy($simg);   // Destroying The Temporary Image
      imagedestroy($dimg);   // Destroying The Other Temporary Image
      print 'Image thumbnail created successfully.';   // Resize successful
    } else {
      print '<font color="#FF0000">ERROR: Unable to upload image.</font>';   // Error Message If Upload Failed
    }
  } else {
    print '<font color="#FF0000">ERROR: Wrong filetype (has to be a .jpg or .jpeg. Yours is ';   // Error Message If Filetype Is Wrong
    print $file_ext;   // Show The Invalid File's Extention
    print '.</font>';
  }
}

[kenrbnsn]

Here's what I use:

<?php
	$tn = imagecreatetruecolor($w, $h);
	$img = imagecreatefromjpeg($fn);
	imagecopyresampled($tn, $img, 0, 0, 0, 0, $w, $h, $ow, $oh);
?>

$ow is the original width of image

$oh is the original height

$fn is the file

 

Ken

[aebstract]

Where are you setting new heights? $w and $h?

[kenrbnsn]

<?php
                list($ow, $oh, $type, $attr) = getimagesize($fn);
	if ($oh > $ow) {
		$th = 160;
		$tw = ($th / $oh) * $ow;
	}
	if ($ow >= $oh) {
		$tw = 160;
		$th = ($tw / $ow) * $oh;
	}
	$w = round($tw);
	$h = round($th);
?>

My thumbnails have a max height or width of 160 px.

 

Ken

[aebstract]

My script looks just about the same, and my max is 200 width, no max height. So I am resizing dependent on the width. Here is an update:

 

$idir = "gallery/$_POST[category]/";   // Path To Images Directory
$tdir = "gallery/$_POST[category]/thumbs/";   // Path To Thumbnails Directory
$twidth = "200";   // Maximum Width For Thumbnail Images
$theight = "900";   // Maximum Height For Thumbnail Images

// Uploading/Resizing Script
  $url = $_FILES['imagefile']['name'];   // Set $url To Equal The Filename For Later Use
  if ($_FILES['imagefile']['type'] == "image/jpg" || $_FILES['imagefile']['type'] == "image/jpeg" || $_FILES['imagefile']['type'] == "image/pjpeg") {
    $file_ext = strrchr($_FILES['imagefile']['name'], '.');   // Get The File Extention In The Format Of , For Instance, .jpg, .gif or .php
    $copy = copy($_FILES['imagefile']['tmp_name'], "$idir" . $_FILES['imagefile']['name']);   // Move Image From Temporary Location To Permanent Location
    if ($copy) {   // If The Script Was Able To Copy The Image To It's Permanent Location
      print 'Image uploaded successfully.<br />';   // Was Able To Successfully Upload Image
      $simg = imagecreatefromjpeg("$idir" . $url);   // Make A New Temporary Image To Create The Thumbanil From
      $currwidth = imagesx($simg);   // Current Image Width
      $currheight = imagesy($simg);   // Current Image Height




$newwidth = 200;
$deci = 200 / $currwidth;
$newheight = $currheight * $deci;




    $dimg = imagecreate($newwidth, $newheight);   // Make New Image For Thumbnail
      imagetruecolortopalette($simg, false, 256);   // Create New Color Pallete
      $palsize = ImageColorsTotal($simg);
      for ($i = 0; $i < $palsize; $i++) {   // Counting Colors In The Image
       $colors = ImageColorsForIndex($simg, $i);   // Number Of Colors Used
       ImageColorAllocate($dimg, $colors['red'], $colors['green'], $colors['blue']);   // Tell The Server What Colors This Image Will Use
      }
      imagecopyresampled($dimg, $simg, 0, 0, 0, 0, $newwidth, $newheight, $currwidth, $currheight);   // Copy Resized Image To The New Image (So We Can Save It)
      imagejpeg($dimg, "$tdir" . $url);   // Saving The Image
      imagedestroy($simg);   // Destroying The Temporary Image
      imagedestroy($dimg);   // Destroying The Other Temporary Image
      print 'Image thumbnail created successfully.';   // Resize successful
    } else {
      print '<font color="#FF0000">ERROR: Unable to upload image.</font>';   // Error Message If Upload Failed
    }
  } else {
    print '<font color="#FF0000">ERROR: Wrong filetype (has to be a .jpg or .jpeg. Yours is ';   // Error Message If Filetype Is Wrong
    print $file_ext;   // Show The Invalid File's Extention
    print '.</font>';
  }
}

 

I changed the imagecopyresized to imagecopyresampled and it didn't affect anything.

 

[kenrbnsn]

If you can send me the original, I will process through my script and see what it looks like.

 

Ken

[aebstract]

Sure, you can try this one:

http://outlawracing.com/gallery/Flyers/huntsvillecard.jpg

be cool if you got it to do 200 width just for testing.

[litebearer]

You need to add the quality variable in when you save (use 100)

http://php.net/manual/en/function.imagejpeg.php

[aebstract]

You need to add the quality variable in when you save (use 100)

http://php.net/manual/en/function.imagejpeg.php

 

   

imagejpeg($dimg, "$tdir" . $url, 100);  // Saving The Image

 

this seems to actually look a bit better as far as save quality, maybe now it's a resizing (size) issue?

[947740]

It might be better if you use the same image for a true comparison.

[aebstract]

 

<- before | after ->

[kenrbnsn]

You can test different sized thumbnails at http://rbnsn.com/phpfreaks/thumb_test.php?s=200

 

to change the size of the thumbnail change the value of "s".

 

Ken

[aebstract]

s = height, right?

Anyway, I played around a little and made a big thumbnail just to see save quality, did a 600 width on mine and (I guess 600 height) on yours. Check out how mine came out:

http://outlawracing.com/gallery/Flyers/thumbs/huntsvillecard.jpg

[kenrbnsn]

Yes, s = height. If you do a s=900 on mine, the image is almost the same as yours.

 

Ken

[aebstract]

For size yes, but did you look at the quality difference in the two?

 

http://rbnsn.com/phpfreaks/thumb_test.php?s=900

http://outlawracing.com/gallery/Flyers/thumbs/huntsvillecard.jpg

 

I'm thinking it has something to do with this:

 

      ImageColorAllocate($dimg, $colors['red'], $colors['green'], $colors['blue']);  // Tell The Server What Colors This Image Will Use

 

When you look at it bigger like that, it's like it doesn't have enough colors to represent the image correctly?

[mattal999]

Although, there is a severe quality difference between the two. I just checked, and the colours look very different.

 

What version of PHP and imagegd are you running? If you don't know how to check, then run this script as a new file:

 

<?php

phpinfo();

?>

 

--- EDIT ---

Try this:

 

<?php

$idir = "gallery/$_POST[category]/";   // Path To Images Directory
$tdir = "gallery/$_POST[category]/thumbs/";   // Path To Thumbnails Directory
$twidth = "200";   // Maximum Width For Thumbnail Images
$theight = "900";   // Maximum Height For Thumbnail Images

// Uploading/Resizing Script
  $url = $_FILES['imagefile']['name'];   // Set $url To Equal The Filename For Later Use
  if ($_FILES['imagefile']['type'] == "image/jpg" || $_FILES['imagefile']['type'] == "image/jpeg" || $_FILES['imagefile']['type'] == "image/pjpeg") {
    $file_ext = strrchr($_FILES['imagefile']['name'], '.');   // Get The File Extention In The Format Of , For Instance, .jpg, .gif or .php
    $copy = copy($_FILES['imagefile']['tmp_name'], "$idir" . $_FILES['imagefile']['name']);   // Move Image From Temporary Location To Permanent Location
    if ($copy) {   // If The Script Was Able To Copy The Image To It's Permanent Location
      print 'Image uploaded successfully.<br />';   // Was Able To Successfully Upload Image
      $simg = imagecreatefromjpeg("$idir" . $url);   // Make A New Temporary Image To Create The Thumbanil From
      $currwidth = imagesx($simg);   // Current Image Width
      $currheight = imagesy($simg);   // Current Image Height
      $newwidth = 200;
      $deci = 200 / $currwidth;
      $newheight = $currheight * $deci;
      $dimg = imagecreatetruecolor($newwidth, $newheight);   // Make New Image For Thumbnail
      imagecopyresampled($dimg, $simg, 0, 0, 0, 0, $newwidth, $newheight, $currwidth, $currheight);   // Copy Resized Image To The New Image (So We Can Save It)
      imagejpeg($dimg, "$tdir" . $url, 100);   // Saving The Image
      imagedestroy($simg);   // Destroying The Temporary Image
      imagedestroy($dimg);   // Destroying The Other Temporary Image
      print 'Image thumbnail created successfully.';   // Resize successful
    } else {
      print '<font color="#FF0000">ERROR: Unable to upload image.</font>';   // Error Message If Upload Failed
    }
  } else {
    print '<font color="#FF0000">ERROR: Wrong filetype (has to be a .jpg or .jpeg. Yours is ';   // Error Message If Filetype Is Wrong
    print $file_ext;   // Show The Invalid File's Extention
    print '.</font>';
  }
}

?>

[aebstract]

GD: FreeType Version 2.2.1

PHP: Version 5.2.13

[mattal999]

Ok that sounds about right. Try the edited part of the post above, and see if it makes any difference.

[kenrbnsn]

Try mine again. I changed the output quality to '100' from the default of '75'.

 

GD Version bundled (2.0.34 compatible)

PHP Version 5.2.9

 

Ken

[aebstract]

Ok that sounds about right. Try the edited part of the post above, and see if it makes any difference.

 

http://outlawracing.com/gallery/Flyers/thumbs/huntsvillecard.jpg

Changed 200 to 600 just to look at quality in a better size. Do you mind explaining what you did to fix this? It seems that whole color portion isn't there anymore.

I think this will work!

 

 

Here's another example:

SO much better!! Thanks a lot.

[mattal999]

Glad it's working!

 

The solution: I actually noticed a difference in Ken's code to yours, which was the fact that he was creating a true colour image using a built in function. Your code was trying to manipulate a standard image (i'm assuming it has limited colour palettes) to become a true colour image. That was what the imageColorAllocate function was doing.

 

All I did was get rid of the block of code that did this, and replace the imagecreate() function with imagecreatetruecolor().