Image editing using ImageMagick PHP library -

i developing image editor, write text on images on position x,y, need draw white image on image called white out. white image drawn @ position cord x, cord y , dynamic size of image width, height. write code not getting image on right coordinates , height width of image. here image rendering function.

 $image = new imagick('image.jpg');      $diagnose=$this->input->post('diagnoses');       $fontsize=$this->input->post('fontsize');     $fontstyle=$this->input->post('fontstyle');          $cordx   = $this->input->post('posx');          $cordy   = $this->input->post('posy');          $font_size = 20;         // watermark text         //$diagnose = "hello world.{newline}it's beautiful day.";           $textlinesarray = explode("{newline}",$diagnose);          // create new drawing palette         $draw = new imagickdraw();          // set font properties         $draw->setfont('arial');         $draw->setfontsize($font_size);         $draw->setfillcolor('black');          // position text @ bottom-right of image         $draw->setgravity(imagick::gravity_northwest);          $i = 0;         foreach ($textlinesarray $index => $text) {                 $newy = ($i * $font_size)  + $cordy;              //echo $newy . "</br>";              //echo $text;              // draw text on image              $image->annotateimage($draw,  $cordx, $newy,0, $text);              $i++;          }          $draw->setfillcolor('magenta');    // set colors use fill , outline         $draw->setstrokecolor( new imagickpixel( 'cyan' ) );         $draw->setstrokewidth(2);         $draw->rectangle($cordx, $cordy, 200, 300);    // draw rectangle           $image->drawimage( $draw );          // set output image format         $image->setimageformat('png');          // output new image         header('content-type: image/png');         echo $image; 

here output, need color box dynamic width height , position