function ask() { var bsh=prompt('See the default brightness, saturation, hue settings, black point %, white point % and change as desired ... 100,0,100,90,95 is grayscale ... darkest 90% of pixels are turned black, the brightest 5% are made white, and those between 90% and 95% are grey-scaled', document.getElementById('brightness').value + ',' + document.getElementById('saturation').value + ',' + document.getElementById('hue').value + ',' + document.getElementById('blackpoint').value + ',' + document.getElementById('whitepoint').value); if (bsh != null) { if (eval('' + bsh.split(',').length) == 5) { document.getElementById('brightness').value=bsh.split(',')[0]; document.getElementById('saturation').value=bsh.split(',')[1]; document.getElementById('hue').value=bsh.split(',')[2]; document.getElementById('blackpoint').value=bsh.split(',')[3]; document.getElementById('whitepoint').value=bsh.split(',')[4]; } } return true; }

Imagick Ideas

RJM Programming - August, 2024 ... thanks to https://www.php.net/manual/en/book.imagick.php and https://www.php.net/manual/en/imagick.contraststretchimage.php





 
"; } else { if (isset($_GET['image'])) { header('Content-type: image/jpeg'); //Instantiate a new Imagick object $image = new Imagick(realpath(urldecode($_GET['image']))); $image->negateImage(false); // If 0 is provided as a width or height parameter, // aspect ratio is maintained $image->thumbnailImage(100, 0); echo $image; exit; } else { //Instantiate a new Imagick object $image = new Imagick(realpath(urldecode($_POST['image']))); list($width, $height) = array_values ($image->getImageGeometry()); $b=(isset($_POST['brightness']) ? $_POST['brightness'] : '100'); $s=(isset($_POST['saturation']) ? $_POST['saturation'] : '0'); $h=(isset($_POST['hue']) ? $_POST['hue'] : '100'); $bp=(isset($_POST['blackpoint']) ? $_POST['blackpoint'] : '90'); $wp=(isset($_POST['whitepoint']) ? $_POST['whitepoint'] : '95'); $image->modulateImage($b, $s, $h); $image->contrastStretchImage($width * $height * ($bp / 100.0), $width * $height * ($wp / 100.0)); $image->writeImage('example_thumbnail.jpg'); echo "

My Changed Image " . urldecode($_POST['image']) . " ... brightness " . $b . ", saturation " . $s . ", hue " . $h . ", black point % " . $bp . "%, white point % " . $wp . "%


"; exit; } } ?>