how to change size of images to specific values?

[mcfbn]

Hi.

I have the following php-code which resizes an image to 25% of the original size:

$src_img = imagecreatefromjpeg("01.jpg");

$new_width = imagesx($src_img) / 4;
$new_height = imagesy($src_img) / 4;

$dst_img = imagecreatetruecolor($new_width,$new_height);

 imagecopyresampled($dst_img,$src_img,0,0,0,0,$new_
 width,$new_height,imagesx($src_img),imagesy($src_i
mg));

imagejpeg($dst_img, "new_file.jpg", 50);      

That works fine but I have a HTML-Table with more than one images and all need to have the same size. Because the original images aren't always the same size, a resizing about 25% is senseless because the small images would be in different sizes.

If i set the values img width & img height in the html-code, the image gets distorted.

Is there a way to solve this problem?

Thanks,
Frank

[Phantazm]

Here's a function I use to "capture" an uploaded image, create a thumbnail (properly resized.. non distorted) and save both to a database... now, before anyone says anything, I store them in a DB because my client SPECIFICALLY requested it... 🙂

Anyway, here's the proggie.

<?php
  // array[0]=width (Of Thumbnail)
  // array[1]=height (Of Thumbnail)
  include ("global.php");
  MYSQL_CONNECT("localhost","secret","anothersecret");
  mysql_select_db("eba");
  $dat = fopen("$p_data", "rb");
  $data = fread($dat, filesize($p_data));    

  $im = ImageCreateFromString($data);
  $imagemax[0]=200;
  $imagemax[1]=150;
  $imagedim[0]=ImageSX($im);
  $imagedim[1]=ImageSY($im);
  if (ceil($imagedim[0]/4) > ceil($imagedim[1]/3))
  {
    $x=0;
    $y=1;
  }
  else
  {
    $x=1;
    $y=0;
  }
  $imageprop=($imagemax[$x]*100)/$imagedim[$x];
  $imagesize[$y]=($imagedim[$y]*$imageprop)/100 ;
  $imagedim[$x]=$imagemax[$x]; 
  $imagedim[$y]=ceil($imagesize[$y]);
  $newimagedim[$x]=$imagedim[$x];
  $newimagedim[$y]=$imagedim[$y];
  $dst_img=@imagecreate($newimagedim[0],$newimagedim[1]); 
  $src_img=@imagecreatefromstring($data);
  ImageCopyResampleBicubic($dst_img,$src_img,0,0,0,0,$newimagedim[0],$newimagedim[1],ImageSX($src_img),ImageSY($src_img)); 
  $filler_img=@imagecreate($imagemax[0],$imagemax[1]);
  $adj_w=($imagemax[0]/2)-ceil($newimagedim[0]/2);
  $adj_h=($imagemax[1]/2)-ceil($newimagedim[1]/2);
  @imagecopy($filler_img, $dst_img, $adj_w, $adj_h, 0, 0, $newimagedim[0], $newimagedim[1]);
  ob_start();
    imagejpeg($filler_img);
    $myimage=ob_get_contents();
  ob_end_clean();
  $data = addslashes($data);
  $dst_img = addslashes($myimage);
  // Check For Moderation Bypass
  if ($bypassmod=="yes")
  {
    $moderated=1;
  }
  else
  {
    $moderated=0;
  }
  $result=MYSQL_QUERY("INSERT INTO pictures (PicModerated,PicData,PicThumbnail,PicDescription,PicCategory1) VALUES ($moderated,'$data','$dst_img','$p_desc','$cat')") or die("Error inserting record");
  MYSQL_CLOSE();
  header("Location: [url]http://myclientshost[/url]");
?>

If you look closely, you'll notice that this my thumbnails are 200x150 (a 4x3 aspect ratio). This script determines whether the image needs horizontal or vertical "padding" and resizes appropriately.

By all means, post any questions.. Hope this helps and sorry for the lack of comments in the script. I'm kinda bad about that sometimes 😉

[mcfbn]

it's very difficult to read the code without comments 😉

what does this mean:

  if (ceil($imagedim[0]/4) > ceil($imagedim[1]/3))

i think imagedim[0] = height of image and imagedim[1] = width of image, but why /4 or /3 ?

[Weedpacket]

Originally posted by mcfbn
what does this mean:

  if (ceil($imagedim[0]/4) > ceil($imagedim[1]/3))

i think imagedim[0] = height of image and imagedim[1] = width of image, but why /4 or /3 ? [/B]

At a wild guess, to determine whether the image has a portrait or landscape aspect ratio, with those whose aspect ratio is less than that of a monitor screen (4/3) regarded as "pretty much square".

[mcfbn]

I got it right like the customer wants it. Thanks :-)

[Phantazm]

Originally posted by mcfbn
it's very difficult to read the code without comments 😉

what does this mean:

  if (ceil($imagedim[0]/4) > ceil($imagedim[1]/3))

i think imagedim[0] = height of image and imagedim[1] = width of image, but why /4 or /3 ? [/B]

Sorry again for the lack of comments (I'd do pretty bad on a "programming team.. eh).

Anyway, Weedpacket's reply is correct. The values (4 and 3) are what 200x150 reduce to (divide each # by 50 and you get 4x3).

Anyway, it' simply the aspect ratio of of the thumbnail being created. The script uses these numbers to determine where the original image needs to be "padded" in the creation of the new image (thumbnail).

Without that statement, the entire script would be useless.

-= Note =-

Frankly, the "if (ceil($imagedim[0]/4) > ceil($imagedim[1]/3))" statement would be better if it used the $imagemax array to determine the aspect ratio and used those figures instead of the hard coded 4x3. The reason it's not that way is simply because I did not specifically write this script for distribution, but with a very specific purpose in mind.

Again, I apologize to everyone for the lack of comments in the script. I'll try to clean it up into a useful function with comments later and repost.

🙂

-= Edit =-

Oh yea, anything in an array that has to do with image dimensions are as follows (as says the only comment in the script 🙂)

  // array[0]=width
  // array[1]=height

[jonki]

First I would like to say thank you ever so much to Phantazm for the code you posted. It has helped me enourmously!!!

I have just one question to whoever can help - Is there a way of changing the background color of the filler? It comes out black but I was hoping there would be an easy way to change it to white for example.

Many Many thanks

Jon

[Weedpacket]

Basically, the first colour you allocate is the one that's used for the background. There's an example given in the example for [man]imagecreate[/man].

[jonki]

Many Thanks Weedpacket,

I finally got round it by writing this code:

  $background_color = imagecolorallocate($filler_img, 255, 255, 255); 
  imagefill($filler_img, 0,0, $background_color); 

It works beautifully. If anyone want a code to resize a picture to any size you want, irrelevant of the aspect ratio, and the to save is as a jpg then just let me know. It is basically what Phantazm wrote with a few minor modifications.

Thanks again to everyone who has helped me out on this forum.