imagecopyresized() question

[nbewley]

Hi there,

I have successfully created a script that uploads images and copies them via gd.

    list($width, $height) = getimagesize($file_tmp);
           //calculate the image ratio
           $imgratio=$width/$height;
           if ($imgratio>1){
              $newwidth = $ThumbWidth;
              $newheight = $ThumbWidth/$imgratio;
           }else{
                 $newheight = $ThumbWidth;
                 $newwidth = $ThumbWidth*$imgratio;
           }
           //function for resize image.
           $resized_img = imagecreatetruecolor($newwidth,$newheight);
           $img_name = $rand_name.$file_ext;
           //the resizing is going on here!
           imagecopyresized($resized_img, $new_img, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 

I would like to make the script check to see if the image width is greater than 700px. If it is, I would like to save the image to new dimensions with 700px the max width; otherwise, just save the image as is.

Can you help me structure my if/else to properly accomplish this?

My thoughts are that I would say something like this:

if ($newwidth > 700) {
$newwidth = 700;
$newheight = ($newwidth * $imgratio)
} else {
//continue as planned 

Any thoughts are greatly appreciated. Thank you.

[StarLion]

Set $thumbwidth to 700, and you'll never get an image wider than 700.

If imagewidth > imageheight;
Newwidth = thumbwidth = 700
If imagewidth < imageheight
Newwidth = thumbwidth * ratio. Ratio (imagewidth/imageheight) must be less than 1, so thumbwidth * ratio must be less than thumbwidth (700);

[nbewley]

Sorry to be obtuse, but do you mean like this:

           if ($imgratio>1){
              $newwidth = $ThumbWidth;
              $newheight = $ThumbWidth/$imgratio;
              //=================
            
           }else{
                 $newheight = $ThumbWidth;
                 $newwidth = $ThumbWidth*$imgratio;
           }
           
           if ($newwidth > $newheight) {
            $newwidth = $ThumbWidth = 700;
           }
           
           if ($newwidth < $newheight) {
            $newwidth = $ThumbWidth * $imgratio;
           }
           
           //function for resize image.
           $resized_img = imagecreatetruecolor($newwidth,$newheight); 

If so, at what point do I make the new height for to match the 700 px width?

[mickyginger]

I had to do this myself just the other day:

function resizeImage($source, $destination, $target_width){
    $success = false;
    $dims = getimagesize($source);
    $width = $dims[0];
    $height = $dims[1];
    $ratio = $width/$height;
    
    $target_height = $target_width*$ratio;
    $thumb = imagecreatetruecolor($target_width, $target_height);
    $source = imagecreatefromjpeg($source);
    imagecopyresampled($thumb, $source, 0, 0, 0, 0, $target_width, $target_height, $width, $height);
    
    if(imagejpeg($thumb, $destination)) $success = true;
    
    return $success;
}

$max_image_width = 700; //set image width here
$dims = getimagesize($filename);
if($dims[1] > $max_image_width){
    if(!resizeImage($upload_filename, $destination_filename, $max_image_width)){
        echo 'There was an error copying image';
        exit();
    }
} 

Any good?

[StarLion]

No, I mean the script you have already does this - think of it this way. If $ThumbWidth has a value of 700 at the start of your script; what are the possible values of $newwidth at the end?

[nbewley]

Thanks for the responses. I feel very close to a solution. I have figured out how to resize width, but not height. If the image width is greater than 700, I set the width to 700. But I haven't been able to change the height proportionally! The image is stretched as a result. Any ideas?

                if ($width>700) {
                    $newwidth = 700;
                    $newheight = $newwidth * $imgratio;
                    
                    if($file_type == "image/pjpeg" || $file_type == "image/jpeg"){
                           $new_img = imagecreatefromjpeg($file_tmp);
                       }elseif($file_type == "image/pjpg" || $file_type == "image/jpg"){
                           $new_img = imagecreatefromjpeg($file_tmp);
                       }elseif($file_type == "image/x-png" || $file_type == "image/png"){
                           $new_img = imagecreatefrompng($file_tmp);
                       }elseif($file_type == "image/gif"){
                           $new_img = imagecreatefromgif($file_tmp);
                       }
                    
                    
                       $file_tmp = imagecreatetruecolor($newwidth,$newheight);
                    imagecopyresized($file_tmp, $new_img, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
                       //finally, save the image
                       ImageJpeg ($file_tmp, $bigpath);
                       ImageDestroy ($file_tmp);
                       ImageDestroy ($new_img); 

Thanks for the advice.

[StarLion]

Turn your * into a / and see what happens.
(nw/nh = w/h)
(nw/nh = r)
(nw = r * nh)
(nw/r = nh)

OT: Go go Algebra skills...whoever said you'd never use them.

[nbewley]

Thanks StarLion.

My math teacher would definitely be a little disappointed with my algebra. Thanks for helping me understand that a bit better.

I now have figured out how to resize the image properly and save it to my database, etc. For some reason, however, I have not figured out how to make a thumbnail for the new re-sized 700 px image. I am properly thumbnailing for regular images perfectly, however. If anyone has a moment I could use an extra pair of eyes to help me see my mistake:

list($width, $height) = getimagesize($file_tmp);
       //calculate the image ratio
       $imgratio=$width/$height;
                
            if ($width>700) {
                    $newwidth = 700;
                    $newheight = $newwidth / $imgratio;
                    
                    if($file_type == "image/pjpeg" || $file_type == "image/jpeg"){
                           $new_img = imagecreatefromjpeg($file_tmp);
                       }elseif($file_type == "image/pjpg" || $file_type == "image/jpg"){
                           $new_img = imagecreatefromjpeg($file_tmp);
                       }elseif($file_type == "image/x-png" || $file_type == "image/png"){
                           $new_img = imagecreatefrompng($file_tmp);
                       }elseif($file_type == "image/gif"){
                           $new_img = imagecreatefromgif($file_tmp);
                       }
                    
                    
                       $file_tmp = imagecreatetruecolor($newwidth,$newheight);
                       imagecopyresized($file_tmp, $new_img, 0, 0, 0, 0, $newwidth, $newheight, $wi                                       dth, $height);
                       //finally, save the image
                       ImageJpeg ($file_tmp, $bigpath);
                       ImageDestroy ($file_tmp);
                        
                                 if ($imgratio>1){
                                      $new2width = $ThumbWidth;
                                      $new2height = $ThumbWidth/$imgratio;
                                      //=================
                                    
                                 }else{
                                         $new2height = $ThumbWidth;
                                         $new2width = $ThumbWidth*$imgratio;
                                   
                                              //function for resize image.
                                       $resized_img = imagecreatetruecolor($new2width,$n                                                                    ew2height);
                                       //the resizing is going on here!
                                       imagecopyresized($resized_img, $new_img, 0, 0, 0,                                                                      0, $new2width, $new2height, $width, $height);
                                       //finally, save the image
                                       ImageJpeg ($resized_img, $thumbpath);
                                       ImageDestroy ($resized_img);
                                       ImageDestroy ($new_img);
                                       
                                 } 

Thanks everyone for the support in trying to figure out this issue. I really appreciate it.

[StarLion]

what do you do if $width is not > 700? Cause... you've got a very large dangling if there.

[nbewley]

Thanks for your reply StarLion. This is the "else" to that "if":

} else
       if($file_size){
          if($file_type == "image/pjpeg" || $file_type == "image/jpeg"){
               $new_img = imagecreatefromjpeg($file_tmp);
           }elseif($file_type == "image/pjpg" || $file_type == "image/jpg"){
               $new_img = imagecreatefromjpeg($file_tmp);
           }elseif($file_type == "image/x-png" || $file_type == "image/png"){
               $new_img = imagecreatefrompng($file_tmp);
           }elseif($file_type == "image/gif"){
               $new_img = imagecreatefromgif($file_tmp);
           }
           //list the width and height and keep the height ratio.
           list($width, $height) = getimagesize($file_tmp);
           //calculate the image ratio
           $imgratio=$width/$height;
           if ($imgratio>1){
              $newwidth = $ThumbWidth;
              $newheight = $ThumbWidth/$imgratio;
              //=================
            
           }else{
                 $newheight = $ThumbWidth;
                 $newwidth = $ThumbWidth*$imgratio;
           }
           //function for resize image.
           $resized_img = imagecreatetruecolor($newwidth,$newheight);
           //the resizing is going on here!
           imagecopyresized($resized_img, $new_img, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
           //finally, save the image
           ImageJpeg ($resized_img, $thumbpath);
           ImageDestroy ($resized_img);
           ImageDestroy ($new_img);         
        }
        //ok copy the finished file to the thumbnail directory
        move_uploaded_file ($file_tmp, $bigpath); 

This is the piece of code that I based the other re-sizing on, also. Everything works as intended except creating the thumbnails as described in my other post.

Thanks for helping me out with this.

[StarLion]

Take a look at where the code in post 10 has the end of the inner Else. Then look at your code in post 8. Spot the difference?