Hello,

Pls is anything wrong with my script below? when ever I upload & crop a PNG image, it comes with black background, what do I do or which crop, resize & upload script is better?

<?php
// Adam Khoury PHP Image Function Library 1.0
// -------------- RESIZE FUNCTION -------------
// Function for resizing any jpg, gif, or png image files
function ak_img_resize($target, $newcopy, $w, $h, $ext) {
list($w_orig, $h_orig) = getimagesize($target);
$scale_ratio = $w_orig / $h_orig;
if (($w / $h) > $scale_ratio) {
$w = $h * $scale_ratio;
} else {
$h = $w / $scale_ratio;
}
$img = "";
$ext = strtolower($ext);
if ($ext == "gif"){
$img = imagecreatefromgif($target);
} else if($ext =="png"){
$img = imagecreatefrompng($target);
} else {
$img = imagecreatefromjpeg($target);
}
$tci = imagecreatetruecolor($w, $h);
// imagecopyresampled(dst_img, src_img, dst_x, dst_y, src_x, src_y, dst_w, dst_h, src_w, src_h)
imagecopyresampled($tci, $img, 0, 0, 0, 0, $w, $h, $w_orig, $h_orig);
if ($ext == "gif"){
imagegif($tci, $newcopy);
} else if($ext =="png"){
imagepng($tci, $newcopy);
} else {
imagejpeg($tci, $newcopy, 84);
}
}
// ------------- THUMBNAIL (CROP) FUNCTION -------------
// Function for creating a true thumbnail cropping from any jpg, gif, or png image files
function ak_img_thumb($target, $newcopy, $w, $h, $ext) {
list($w_orig, $h_orig) = getimagesize($target);
$src_x = ($w_orig / 2) - ($w / 2);
$src_y = ($h_orig / 2) - ($h / 2);
$ext = strtolower($ext);
$img = "";
if ($ext == "gif"){
$img = imagecreatefromgif($target);
} else if($ext =="png"){
$img = imagecreatefrompng($target);
} else {
$img = imagecreatefromjpeg($target);
}
$tci = imagecreatetruecolor($w, $h);
imagecopyresampled($tci, $img, 0, 0, $src_x, $src_y, $w, $h, $w, $h);
if ($ext == "gif"){
imagegif($tci, $newcopy);
} else if($ext =="png"){
imagepng($tci, $newcopy);
} else {
imagejpeg($tci, $newcopy, 84);
}
}
?>

I am not a coder but looking here

 

imagecopyresampled($tci, $img, 0, 0, 0, 0, $w, $h, $w_orig, $h_orig);

Are those four zeros a colour code for black?

 

I could be completely wrong.

Is the PNG image you're uploading transparent?

Thanks Guys,

 

@ Jack, Yes the PNG is transparent

 

@ Fuzzy Logic, You may be right. Let me give it a check.

@ Jack, Yes the PNG is transparent

 

As is 100% blank? If it's transparent I think the default for a canvas is black.

 

I just made an image thingy and I used this guide by Salman Arshad for the crop and resample which uses the GD library and a nice method for detecting file type other than relying just on extension.

As is 100% blank? If it's transparent I think the default for a canvas is black.

That's what I was thinking.

 

Amending the line that appears to set a black background could work?!

imagecopyresampled($tci, $img, 0, 0, 0, 0, $w, $h, $w_orig, $h_orig);

imagecopyresampled($tci, $img, $w, $h, $w_orig, $h_orig);

Aha, see this post ... the cracks are look into imagealphablending() and imagesavealpha().

Thanks all, will try them

I am not a coder but looking here

 

 

Are those four zeros a colour code for black?

 

I could be completely wrong.

Those 4 zeros are for setting the destination x and y and the src x and y. However to help the OP better here is a simple class I built a while back to handle image re sizing of all image types.

class imageResize {
  private $img;
  private $type;
/**Method of loading an image**/
  public function loadImg($file) {
    $info = getimagesize($file);
    $this->type = $info[2];
/**Switch through image types**/
    switch ($this->type) {
      case IMAGETYPE_JPEG :
        $this->img = imagecreatefromjpeg($file);
        break;
      case IMAGETYPE_GIF :
        $this->img = imagecreatefromgif($file);
        break;
      case IMAGETYPE_PNG :
        $this->img = imagecreatefrompng($file);
        break;
    }
  }
/**Image save**/
  public function saveImg($file, $type = IMAGETYPE_JPEG, $com = 75) {
/**Switch through image types**/
    switch ($this->type) {
      case IMAGETYPE_JPEG :
        imagejpeg($this->img, $file, $com);
        break;
      case IMAGETYPE_GIF :
        imagegif($this->img, $file);
        break;
      case IMAGETYPE_PNG :
        imagepng($this->img, $file);
        break;
    }
  }
/**Image height**/
  public function imgHeight() {
    return imagesy($this->img);
  }
/**Image width**/
  public function imgWidth() {
    return imagesx($this->img);
  }
/**Resize the image**/
  public function resizeImg($w, $h) {
    $new = imagecreatetruecolor($w, $h);
    imagecopyresampled($new, $this->img, 0, 0, 0, 0, $w, $h, $this->imgWidth(), $this->imgHeight());
    $this->img = $new;
  }
}

Here is an example

$image = new imageResize;

                $image->loadImg('uploads/' . $filename);//Load the image
                $image->resizeImg(494, 352);//Set the width and height
                $image->saveImg('uploads/' . $filename);//Save the image