note 113503 added to function.imagecolorat

This improves upon to my previous function (which only really worked on a few greyscale colours). Colour should now be a hexadecimal colour value. Colour and tolerance are now optional parameters. trimImage ( resource $image [, str $colour [, int $tolerance]] ) trimImage() will return top-most, right-most, bottom-most and left-most positions of wanted pixels for an image (i.e. find minimum image area so you can then trim given colour from the outer edges of an image). Parameters image An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(). colour Hexadecimal value of colour to be 'trimmed'. If omitted the top/left corner colour will be used as default. tolerance Acceptable range +- from colour. Allowable range 0 to 255. If omitted 10 will be used as default. Return Values Returns an array of outermost pixels which are beyond the tolerance range from colour. array( int $top, int $right, int $bottom, int $left ) function trimImage($im,$c=null,$t=10) { // if hex colour ($c) exists attempt to convert to decimal if ($c) $rgb = @hexdec($c); // if hexdec failed to get a value between black (0) and white (16777215) // grab the colour from the top left corner (2 pixels in to avoid messy edges) if (!is_numeric($rgb) || $rgb < 0 || $rgb > 16777215) $rgb = imagecolorat($im, 2, 2); // split $rgb into red, green and blue $r = ($rgb >> 16) & 0xFF; $g = ($rgb >> 8) & 0xFF; $b = $rgb & 0xFF; // make sure tolerance ($t) is a number between 0 - 255 if (!is_numeric($t) || $t < 0) $t = 0; elseif ($t > 255) $t = 255; $w = imagesx($im); $h = imagesy($im); // image width and height for($x = 0; $x < $w; $x++) { for($y = 0; $y < $h; $y++) { $rgb = imagecolorat($im, $x, $y); $red = ($rgb >> 16) & 0xFF; $grn = ($rgb >> 8) & 0xFF; $blu = $rgb & 0xFF; if ( $red < $r-$t || $red > $r+$t || // not trim red (nor within tolerance) $grn < $g-$t || $grn > $g+$t || // not trim green (nor within tolerance) $blu < $b-$t || $blu > $b+$t // not trim blue (nor within tolerance) ) { $y_axis[$y] = $y; $x_axis[$x] = $x; // wanted pixel coordinates stored } } } if (!$y_axis) $y_axis = $x_axis = array(0); // avoid errors if all pixels are trimmed // sort so first and last occurances are at start and end sort($y_axis); sort($x_axis); $t = array_shift($y_axis); // first wanted pixel on Y axis (top) $r = array_pop($x_axis); // last wanted pixel on X axis (right) $b = array_pop($y_axis); // last wanted pixel on Y axis (bottom) $l = array_shift($x_axis); // first wanted pixel on X axis (left) return array($t,$r,$b,$l); } ---- Server IP: 69.147.83.199 Probable Submitter: 124.148.142.99 ---- Manual Page -- http://php.net/manual/en/function.imagecolorat.php Edit -- https://master.php.net/note/edit/113503 Del: integrated -- https://master.php.net/note/delete/113503/integrated Del: useless -- https://master.php.net/note/delete/113503/useless Del: bad code -- https://master.php.net/note/delete/113503/bad+code Del: spam -- https://master.php.net/note/delete/113503/spam Del: non-english -- https://master.php.net/note/delete/113503/non-english Del: in docs -- https://master.php.net/note/delete/113503/in+docs Del: other reasons-- https://master.php.net/note/delete/113503 Reject -- https://master.php.net/note/reject/113503 Search -- https://master.php.net/manage/user-notes.php