PHP Imagick example image scaling to minimize blur and defects.

ScaleToJpg.php

<?php

function ScaleToJpg($src,$width,$height,$dest) {

    $im = new \Imagick($src);
    $im->setImageCompression(\Imagick::COMPRESSION_JPEG);
    $im->setImageCompressionQuality(100);
    $im->stripImage();
    $im->setInterlaceScheme(\Imagick::INTERLACE_PLANE);
    $size = $im->getImageGeometry();    
    
    if($size['width'] >= $size['height']){
      if($size['width'] > $width){
        $im->resizeImage($width, 0, \Imagick::FILTER_SINC, 1);
      }
    } else{
      if($size['height'] > $height){
        $im->resizeImage(0, $height, \Imagick::FILTER_SINC, 1);
      }
    }
    $im->writeimage($dest);
    $im->clear();
    $im->destroy();
    $im = null;
}