Modify image contrast and colours

Original imageModified Image
Unmodified image Modified using colorize
<?php exec("convert House.jpg -fill black -colorize 15% colorize.png"); ?>

More information
Unmodified image Modified using contrast-stretch
<?php exec("convert House.jpg -contrast-stretch 2% stretch.png"); ?>

More information
Unmodified image Modified using level
<?php exec("convert House.jpg -level 5%,95%,0.8 level.png"); ?>

More information
Unmodified image Modified using normalize
<?php exec("convert House.jpg -normalize normalize.png"); ?>

More information
Unmodified image Modified using sigmoidal-contrast
<?php exec("convert House.jpg -sigmoidal-contrast 3,75% sigmoidal.png"); ?>

More information