Gdn_UploadImage::validateUpload PHP Method

    public function validateUpload($InputName, $ThrowError = true)
    {
        if (!function_exists('gd_info')) {
            throw new Exception(T('The uploaded file could not be processed because GD is not installed.'));
        }
        // Make sure that all standard file upload checks are performed.
        $TmpFileName = parent::validateUpload($InputName, $ThrowError);
        // Now perform image-specific checks.
        if ($TmpFileName) {
            $Size = getimagesize($TmpFileName);
            if ($Size === false) {
                throw new Exception(T('The uploaded file was not an image.'));
            }
        }
        return $TmpFileName;
    }

 /**
  * Save an image from a field and delete any old image that's been uploaded.
  *
  * @param string $Field The name of the field. The image will be uploaded with the _New extension while the current image will be just the field name.
  * @param array $Options
  */
 public function saveImage($Field, $Options = array())
 {
     $Upload = new Gdn_UploadImage();
     $FileField = str_replace('.', '_', $Field);
     if (!getValueR("{$FileField}_New.name", $_FILES)) {
         trace("{$Field} not uploaded, returning.");
         return false;
     }
     // First make sure the file is valid.
     try {
         $TmpName = $Upload->validateUpload($FileField . '_New', true);
         if (!$TmpName) {
             return false;
             // no file uploaded.
         }
     } catch (Exception $Ex) {
         $this->addError($Ex);
         return false;
     }
     // Get the file extension of the file.
     $Ext = val('OutputType', $Options, trim($Upload->getUploadedFileExtension(), '.'));
     if ($Ext == 'jpeg') {
         $Ext = 'jpg';
     }
     Trace($Ext, 'Ext');
     // The file is valid so let's come up with its new name.
     if (isset($Options['Name'])) {
         $Name = $Options['Name'];
     } elseif (isset($Options['Prefix'])) {
         $Name = $Options['Prefix'] . md5(microtime()) . '.' . $Ext;
     } else {
         $Name = md5(microtime()) . '.' . $Ext;
     }
     // We need to parse out the size.
     $Size = val('Size', $Options);
     if ($Size) {
         if (is_numeric($Size)) {
             touchValue('Width', $Options, $Size);
             touchValue('Height', $Options, $Size);
         } elseif (preg_match('`(\\d+)x(\\d+)`i', $Size, $M)) {
             touchValue('Width', $Options, $M[1]);
             touchValue('Height', $Options, $M[2]);
         }
     }
     trace($Options, "Saving image {$Name}.");
     try {
         $Parsed = $Upload->saveImageAs($TmpName, $Name, val('Height', $Options, ''), val('Width', $Options, ''), $Options);
         trace($Parsed, 'Saved Image');
         $Current = $this->getFormValue($Field);
         if ($Current && val('DeleteOriginal', $Options, true)) {
             // Delete the current image.
             trace("Deleting original image: {$Current}.");
             if ($Current) {
                 $Upload->delete($Current);
             }
         }
         // Set the current value.
         $this->setFormValue($Field, $Parsed['SaveName']);
     } catch (Exception $Ex) {
         $this->addError($Ex);
     }
 }