ช่วยดูหน่อย function crop รูป ตัวนี้ พอ crop รูป เสร็จแล้ว ทำไมไปดูในไฟล์รูปจริง ขนาดยังเท่าเดิม

<?php

function croptofit($source_path, $desired_width, $desired_height){

//
// Add file validation code here
//

list( $source_width, $source_height, $source_type ) = getimagesize( $source_path );

switch ( $source_type )
{
case IMAGETYPE_GIF:
$source_gdim = imagecreatefromgif( $source_path );
break;

case IMAGETYPE_JPEG:
$source_gdim = imagecreatefromjpeg( $source_path );
break;

case IMAGETYPE_PNG:
$source_gdim = imagecreatefrompng( $source_path );
break;
}

$source_aspect_ratio = $source_width / $source_height;
$desired_aspect_ratio = $desired_width / $desired_height;

if ( $source_aspect_ratio > $desired_aspect_ratio )
{
//
// Triggered when source image is wider
//
$temp_height = $desired_height;
$temp_width = ( int ) ( $desired_height * $source_aspect_ratio );
}
else
{
//
// Triggered otherwise (i.e. source image is similar or taller)
//
$temp_width = $desired_width;
$temp_height = ( int ) ( $desired_width / $source_aspect_ratio );
}

//
// Resize the image into a temporary GD image
//

$temp_gdim = imagecreatetruecolor( $temp_width, $temp_height );
imagecopyresampled(
$temp_gdim,
$source_gdim,
0, 0,
0, 0,
$temp_width, $temp_height,
$source_width, $source_height
);

//
// Copy cropped region from temporary image into the desired GD image
//

$x0 = ( $temp_width - $desired_width ) / 2;
$y0 = ( $temp_height - $desired_height ) / 2;

$desired_gdim = imagecreatetruecolor( $desired_width, $desired_height );
imagecopy(
$desired_gdim,
$temp_gdim,
0, 0,
$x0, $y0,
$desired_width, $desired_height
);



//
// Render the image
// Alternatively, you can save the image in file-system or database
//

header( 'Content-type: image/jpeg' );
imagejpeg( $desired_gdim );

//
// Add clean-up code here
//
}

#using
croptofit('pic/Music_Dancesm.jpg', 100, 100);
?>