Legacy ImageMagick Discussions Archive

This is resolved as no bug, but a typo on my part. I had put a blur=0 for default value, but it should have been 1.

I am by no means an expert at Imagick, but I believe that I have uncovered a bug, if I am not making a mistake.

When I use resizeImage with the lanczos filter, the result is very aliased as if it was using a point filter or using sampleImage.

Here is the input image:

Here is the code using Imagick to resize by 25%

Code: Select all

<?php

// Timer function
function microtime_float()
{
    list($utime, $time) = explode(" ", microtime());
    return ((float)$utime + (float)$time);
}


echo "PHP Loop Imagick<br>";	

// Input image name if used
$image = "testoutline1.png";

// Output image name
$output = "testresize1_imagick.png";

// How many time to run
$run = "1";

// Setup default cycle time
$time = "";

$width = floor(0.25 * 935);

$height = floor(0.25 * 113);

// Start timer
$script_start = microtime_float();

// Loop through the code
For ( $i=1; $i <= $run; $i++ ){

try
{

$im = new Imagick();

$im->readImage( $image );

# erroneous default blur value used
#$im->resizeImage ( $width, $height, Imagick::FILTER_LANCZOS, 0, false ); 

# corrected default blur value
$im->resizeImage ( $width, $height, Imagick::FILTER_LANCZOS, 1, false );

$im->writeImage( $output );


}

catch(Exception $e)
{
        echo $e->getMessage();
}


// End loop
}

// Stop timer
$script_end = microtime_float();

// Calculate the run time
$run_time = ( round( $script_end, 4 ) - round( $script_start, 4 ));

// Calculate the average run time
$average = $run_time/$run;

// Display the average run time
echo "<br><p><b>Average time = $average </b></p>";

// Delete the image created
//unlink($output);
echo "<img src=\"$output\" border=1>";

?>

Here is the resulting CORRECTED image:

Compare this to using PHP exec code:

Code: Select all

<?php

// Timer function
function microtime_float()
{
    list($utime, $time) = explode(" ", microtime());
    return ((float)$utime + (float)$time);
}

echo "PHP Loop exec command<br>";	

// Input image name if used
$image = "testoutline1.png";

// Output image name
$output = "testresize1_exec.png";

// How many time to run
$run = "1";

// Setup default cycle time
$time = "";

// Command to use
$cmd = "-filter lanczos -resize 25% ";

// Start timer
$script_start = microtime_float();

// Loop through the code
For ( $i=1; $i <= $run; $i++ ){

// Run the command
// Create an empty error array
$out = array();

exec("/usr/local/bin/convert $image $cmd $output", $out, $returnval);

// End loop
}

// Stop timer
$script_end = microtime_float();

// Calculate the run time
$run_time = ( round( $script_end, 4 ) - round( $script_start, 4 ));

// Calculate the average run time
$average = $run_time/$run;

// Display the average run time
echo "<br><p><b>Average time = $average </b></p>";

// Delete the image created
//unlink($output);
echo "<img src=\"$output\" border=1>";

?>

Here is the resulting image:

It is possible that the IM filters have been changed since this version of IMagick. I know Anthony has made some significant changes over time. Perhaps Imagick has not kept up with those changes.

I hope the Imagick developer, mkoppanen, can take a look and comment.

Thanks

Fred

P.S. Tests were using: PHP 5.1.6; Imagick 3.00RC1 and IM 6.6.2-9 and 6.6.3-0

Legacy ImageMagick Discussions Archive

RESOLVED-NO BUG: possible bug in resizeImage

RESOLVED-NO BUG: possible bug in resizeImage