Need to convert images to jpg to make thumbnails

When a image is uploaded it creates a thumbnail image, right now it only workes with jpeg, couldent finda funktion that converts other file types like bmp, tif, gif, png to a jpg? How can it be done?

here is the script.

      function resize($imgH, $sizeX, $sizeY) {
      $imgR = imagecreatetruecolor($sizeX, $sizeY);
      imageCopyResized($imgR, $imgH, 0, 0, 0, 0, imageSX($imgR), imageSY($imgR), imageSX($imgH), imageSY($imgH));
 
      return $imgR;
   }

   
$filename_thumb = $new_file_name;
$output = 'thumbnails/'.$filename_thumb;
 
$width_orginal = $width; //Width of the orginal image
$height_orginal = $height; // Height of the orginal image

if($width_orginal > $height_orginal) 
{
$biggest_side = $width_orginal;
$smallest_side = $height_orginal;
}
else 
{
$biggest_side = $height_orginal;
$smallest_side = $width_orginal;
}

$aspect_ratio = ($biggest_side)/($smallest_side);


$short_side = (floor(150/($aspect_ratio)));
if ($short_side == 0) $short_side = 1;

if($width_orginal > $height_orginal) 
{
$new_width = 150;
$new_height = $short_side;
}
else 
{
$new_height = 150;
$new_width = $short_side;
}



 

      $imgH = imageCreateFromJpeg('uploads/'.$filename_thumb);
      imageJpeg(resize($imgH, $new_width, $new_height), $output, 100);

PHP:

 

my gallery2 software uses
ImageMagick
to do such jobs. I also use ImageMagick offline on my linux machine to do such jobs very efficiently.

From man ImageMagick:
ImageMagick suite of tools. Use it to convert between image formats as well as resize an image, blur, crop, despeckle, dither, draw on, flip, join, re-sample, and much more.

normally on most hosts ImageMagick might be preinstalled or it can be installed by you into your user-space.

it's an ideal tool on Linux machines to batch process masses of pics in various formats efficiently.

for more detals about PHP code - you may have a look at the code-modules of gallery2 - it's all open source

 

Seems way more complicated then it needs to be for what im trying to do?

 

To jpg images you are using the functions: imageCreateFromJpeg() and imageJpeg()

To use other formats, try to detect file extension or myme type of the file and then use functions like:
imagecreatefromgif()
imagecreatefrompng()

info+documentation: php.net
etc...

 

Still havent figured out how to convert a iamge from png or gif to jpg...