Image Convert Type Function Upload Tutorial

Learn how to convert images from one type to another using the GD library functions. In this specific video example we convert any uploaded image file to a jpg. my_file.php

<form enctype="multipart/form-data" method="post" action="image_upload_script.php">
Choose your file here:
<input name="uploaded_file" type="file"/><br /><br />
<input type="submit" value="Upload It"/>
</form>

image_upload_script.php

<?php
// Access the $_FILES global variable for this specific file being uploaded
// and create local PHP variables from the $_FILES array of information
$fileName = $_FILES["uploaded_file"]["name"]; // The file name
$fileTmpLoc = $_FILES["uploaded_file"]["tmp_name"]; // File in the PHP tmp folder
$fileType = $_FILES["uploaded_file"]["type"]; // The type of file it is
$fileSize = $_FILES["uploaded_file"]["size"]; // File size in bytes
$fileErrorMsg = $_FILES["uploaded_file"]["error"]; // 0 for false... and 1 for true
$fileName = preg_replace('#[^a-z.0-9]#i', '', $fileName); // filter the $filename
$kaboom = explode(".", $fileName); // Split file name into an array using the dot
$fileExt = end($kaboom); // Now target the last array element to get the file extension

// START PHP Image Upload Error Handling --------------------------------
if (!$fileTmpLoc) { // if file not chosen
    echo "ERROR: Please browse for a file before clicking the upload button.";
    exit();
} else if($fileSize > 5242880) { // if file size is larger than 5 Megabytes
    echo "ERROR: Your file was larger than 5 Megabytes in size.";
    unlink($fileTmpLoc); // Remove the uploaded file from the PHP temp folder
    exit();
} else if (!preg_match("/.(gif|jpg|png)$/i", $fileName) ) {
     // This condition is only if you wish to allow uploading of specific file types    
     echo "ERROR: Your image was not .gif, .jpg, or .png.";
     unlink($fileTmpLoc); // Remove the uploaded file from the PHP temp folder
     exit();
} else if ($fileErrorMsg == 1) { // if file upload error key is equal to 1
    echo "ERROR: An error occured while processing the file. Try again.";
    exit();
}
// END PHP Image Upload Error Handling ----------------------------------
// Place it into your "uploads" folder mow using the move_uploaded_file() function
$moveResult = move_uploaded_file($fileTmpLoc, "uploads/$fileName");
// Check to make sure the move result is true before continuing
if ($moveResult != true) {
    echo "ERROR: File not uploaded. Try again.";
    exit();
}
// Include the file that houses all of our custom image functions
include_once("ak_php_img_lib_1.0.php");
// ---------- Start Universal Image Resizing Function --------
$target_file = "uploads/$fileName";
$resized_file = "uploads/resized_$fileName";
$wmax = 500;
$hmax = 500;
ak_img_resize($target_file, $resized_file, $wmax, $hmax, $fileExt);
// ----------- End Universal Image Resizing Function ----------
// ---------- Start Convert to JPG Function --------
if (strtolower($fileExt) != "jpg") {
    $target_file = "uploads/resized_$fileName";
    $new_jpg = "uploads/resized_".$kaboom[0].".jpg";
    ak_img_convert_to_jpg($target_file, $new_jpg, $fileExt);
}
// ----------- End Convert to JPG Function -----------
// Display things to the page so you can see what is happening for testing purposes
echo "The file named <strong>$fileName</strong> uploaded successfuly.<br /><br />";
echo "It is <strong>$fileSize</strong> bytes in size.<br /><br />";
echo "It is an <strong>$fileType</strong> type of file.<br /><br />";
echo "The file extension is <strong>$fileExt</strong><br /><br />";
echo "The Error Message output for this upload is: $fileErrorMsg";
?>

ak_php_img_lib_1.0.php

<?php
// ----------------------- 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, $newcopy, 84);
    }
}
// ------------------ IMAGE CONVERT FUNCTION -------------------
// Function for converting GIFs and PNGs to JPG upon upload
function ak_img_convert_to_jpg($target, $newcopy, $ext) {
    list($w_orig, $h_orig) = getimagesize($target);
    $ext = strtolower($ext);
    $img = "";
    if ($ext == "gif"){ 
        $img = imagecreatefromgif($target);
    } else if($ext =="png"){ 
        $img = imagecreatefrompng($target);
    }
    $tci = imagecreatetruecolor($w_orig, $h_orig);
    imagecopyresampled($tci, $img, 0, 0, 0, 0, $w_orig, $h_orig, $w_orig, $h_orig);
    imagejpeg($tci, $newcopy, 84);
}
?>