Need to get JPG from scanned TIFF image in php imagick

Question:

There is a scanned TIFF image with parameters 16bit, 14000px X 14000px, 1200dpi. In php imagick I do:

$im->readImage( $DOCUMENT_ROOT.$TifFilePath );  
$im->setImageCompression(Imagick::COMPRESSION_ZIP);
$im->setCompressionQuality(10);
$im->setImageFormat( "jpg" );

I get a file with an image of the same linear dimensions and resolution. The file size is about 40 mb. It is necessary to reduce the size of the output file by an order of magnitude, even at the cost of degrading the image quality. Linear dimensions and resolution must be preserved.

Answer:

Try resizing the image, or scaling it:

        $imagick = new \Imagick;

        $imagick->setResolution(200,200); 

        $imagick->readImage($file);

        $imagick->scaleImage(1920,0);

        $imagick->setImageFormat('jpeg');
        $imagick->setImageCompression(\Imagick::COMPRESSION_JPEG); 
        $imagick->setImageCompressionQuality(55);

        $imagick->writeImages($path.$filename, false);

        $imagick->clear(); 
        $imagick->destroy();