This class allows you to crop an image in a variety of ways. You can crop in an absolute or relative way (to a certain size or by a certain size), both as a pixel number or a percentage. You can also save or display the cropped image. The cropping can be done in 9 different positions: top left, top, top right, left, centre, right, bottom left, bottom, or bottom right. Or you can automatically crop based on a threshold limit. The original image can be loaded from the file system or from a string (for example, data returned from a database.)
The script attempts to auto-detect the GD version, so you should be able to use GD 1.6 and on up.
By : amnuts
<?php
//
// class.cropcanvas.php
// version 1.2.0, 26th November, 2003
//
// Description
//
// This is a class allows you to crop an image in a variety of ways.
// You can crop in an absolute or relative way (to a certain size or
// by a certain size), both as a pixel number or a percentage. You
// can also save or display the cropped image. The cropping can be
// done in 9 different positions: top left, top, top right, left,
// centre, right, bottom left, bottom, or bottom right. Or you can
// crop automatically based on a threshold limit. The original
// image can be loaded from the file system or from a string (for
// example, data returned from a database.)
//
// Author
//
// Andrew Collington, 2003
// php@amnuts.com, http://php.amnuts.com/
//
//
// Feedback
//
// There is message board at the following address:
//
// http://php.amnuts.com/forums/index.php
//
// Please use that to post up any comments, questions, bug reports, etc. You
// can also use the board to show off your use of the script.
//
// Support
//
// If you like this script, or any of my others, then please take a moment
// to consider giving a donation. This will encourage me to make updates and
// create new scripts which I would make available to you. If you would like
// to donate anything, then there is a link from my website to PayPal.
//
// Example of use
//
// require 'class.cropcanvas.php';
// $cc = new canvasCrop();
//
// $cc->loadImage('original1.png');
// $cc->cropBySize(100, 100, ccBOTTOMRIGHT);
// $cc->saveImage('final1.png');
//
// $cc->flushImages();
//
// $cc->loadImage('original2.png');
// $cc->cropByPercent(15, 50, ccCENTER);
// $cc->saveImage('final2.jpg', 90);
//
// $cc->flushImages();
//
// $cc->loadImage('original3.png');
// $cc->cropToDimensions(67, 37, 420, 255);
// $cc->showImage('png');
//
define("ccTOPLEFT", 0);
define("ccTOP", 1);
define("ccTOPRIGHT", 2);
define("ccLEFT", 3);
define("ccCENTRE", 4);
define("ccCENTER", 4);
define("ccRIGHT", 5);
define("ccBOTTOMLEFT", 6);
define("ccBOTTOM", 7);
define("ccBOTTOMRIGHT", 8);
class canvasCrop
{
var $_imgOrig;
var $_imgFinal;
var $_showDebug;
var $_gdVersion;
/**
* @return canvasCrop
* @param bool $debug
* @desc Class initializer
*/
function canvasCrop($debug = false)
{
$this->_showDebug = ($debug ? true : false);
$this->_gdVersion = (function_exists('imagecreatetruecolor')) ? 2 : 1;
}
/**
* @return bool
* @param string $filename
* @desc Load an image from the file system - method based on file extension
*/
function loadImage($filename)
{
if (!@file_exists($filename))
{
$this->_debug('loadImage', "The supplied file name '$filename' does not point to a readable file.");
return false;
}
$ext = strtolower($this->_getExtension($filename));
$func = "imagecreatefrom$ext";
if (!@function_exists($func))
{
$this->_debug('loadImage', "That file cannot be loaded with the function '$func'.");
return false;
}
$this->_imgOrig = @$func($filename);
if ($this->_imgOrig == null)
{
$this->_debug('loadImage', 'The image could not be loaded.');
return false;
}
return true;
}
/**
* @return bool
* @param string $string
* @desc Load an image from a string (eg. from a database table)
*/
function loadImageFromString($string)
{
$this->_imgOrig = @ImageCreateFromString($string);
if (!$this->_imgOrig)
{
$this->_debug('loadImageFromString', 'The image could not be loaded.');
return false;
}
return true;
}
/**
* @return bool
* @param string $filename
* @param int $quality
* @desc Save the cropped image
*/
function saveImage($filename, $quality = 100)
{
if ($this->_imgFinal == null)
{
$this->_debug('saveImage', 'There is no processed image to save.');
return false;
}
$ext = strtolower($this->_getExtension($filename));
$func = "image$ext";
if (!@function_exists($func))
{
$this->_debug('saveImage', "That file cannot be saved with the function '$func'.");
return false;
}
$saved = false;
if ($ext == 'png') $saved = $func($this->_imgFinal, $filename);
if ($ext == 'jpeg') $saved = $func($this->_imgFinal, $filename, $quality);
if ($saved == false)
{
$this->_debug('saveImage', "Could not save the output file '$filename' as a $ext.");
return false;
}
return true;
}
/**
* @return bool
* @param string $type
* @param int $quality
* @desc Shows the cropped image without any saving
*/
function showImage($type = 'png', $quality = 100)
{
if ($this->_imgFinal == null)
{
$this->_debug('showImage', 'There is no processed image to show.');
return false;
}
if ($type == 'png')
{
echo @ImagePNG($this->_imgFinal);
return true;
}
else if ($type == 'jpg' || $type == 'jpeg')
{
echo @ImageJPEG($this->_imgFinal, '', $quality);
return true;
}
else
{
$this->_debug('showImage', "Could not show the output file as a $type.");
return false;
}
}
/**
* @return int
* @param int $x
* @param int $y
* @param int $position
* @desc Determines the dimensions to crop to if using the 'crop by size' method
*/
function cropBySize($x, $y, $position = ccCENTRE)
{
if ($x == 0)
{
$nx = @ImageSX($this->_imgOrig);
}
else
{
$nx = @ImageSX($this->_imgOrig) - $x;
}
if ($y == 0)
{
$ny = @ImageSY($this->_imgOrig);
}
else
{
$ny = @ImageSY($this->_imgOrig) - $y;
}
return ($this->_cropSize(-1, -1, $nx, $ny, $position, 'cropBySize'));
}
/**
* @return int
* @param int $x
* @param int $y
* @param int $position
* @desc Determines the dimensions to crop to if using the 'crop to size' method
*/
function cropToSize($x, $y, $position = ccCENTRE)
{
if ($x == 0) $x = 1;
if ($y == 0) $y = 1;
return ($this->_cropSize(-1, -1, $x, $y, $position, 'cropToSize'));
}
/**
* @return int
* @param int $sx
* @param int $sy
* @param int $ex
* @param int $ey
* @desc Determines the dimensions to crop to if using the 'crop to dimensions' method
*/
function cropToDimensions($sx, $sy, $ex, $ey)
{
$nx = abs($ex - $sx);
$ny = abs($ey - $sy);
return ($this->_cropSize($sx, $sy, $nx, $ny, $position, 'cropToDimensions'));
}
/**
* @return int
* @param int $percentx
* @param int $percenty
* @param int $position
* @desc Determines the dimensions to crop to if using the 'crop by percentage' method
*/
function cropByPercent($percentx, $percenty, $position = ccCENTRE)
{
if ($percentx == 0)
{
$nx = @ImageSX($this->_imgOrig);
}
else
{
$nx = @ImageSX($this->_imgOrig) - (($percentx / 100) * @ImageSX($this->_imgOrig));
}
if ($percenty == 0)
{
$ny = @ImageSY($this->_imgOrig);
}
else
{
$ny = @ImageSY($this->_imgOrig) - (($percenty / 100) * @ImageSY($this->_imgOrig));
}
return ($this->_cropSize(-1, -1, $nx, $ny, $position, 'cropByPercent'));
}
/**
* @return int
* @param int $percentx
* @param int $percenty
* @param int $position
* @desc Determines the dimensions to crop to if using the 'crop to percentage' method
*/
function cropToPercent($percentx, $percenty, $position = ccCENTRE)
{
if ($percentx == 0)
{
$nx = @ImageSX($this->_imgOrig);
}
else
{
$nx = ($percentx / 100) * @ImageSX($this->_imgOrig);
}
if ($percenty == 0)
{
$ny = @ImageSY($this->_imgOrig);
}
else
{
$ny = ($percenty / 100) * @ImageSY($this->_imgOrig);
}
return ($this->_cropSize(-1, -1, $nx, $ny, $position, 'cropByPercent'));
}
/**
* @return bool
* @param int $threshold
* @desc Determines the dimensions to crop to if using the 'automatic crop by threshold' method
*/
function cropByAuto($threshold = 254)
{
if ($threshold < 0) $threshold = 0;
if ($threshold > 255) $threshold = 255;
$sizex = @ImageSX($this->_imgOrig);
$sizey = @ImageSY($this->_imgOrig);
$sx = $sy = $ex = $ey = -1;
for ($y = 0; $y < $sizey; $y++)
{
for ($x = 0; $x < $sizex; $x++)
{
if ($threshold >= $this->_getThresholdValue($this->_imgOrig, $x, $y))
{
if ($sy == -1) $sy = $y;
else $ey = $y;
if ($sx == -1) $sx = $x;
else
{
if ($x < $sx) $sx = $x;
else if ($x > $ex) $ex = $x;
}
}
}
}
$nx = abs($ex - $sx);
$ny = abs($ey - $sy);
return ($this->_cropSize($sx, $sy, $nx, $ny, ccTOPLEFT, 'cropByAuto'));
}
/**
* @return void
* @desc Destroy the resources used by the images
*/
function flushImages()
{
@ImageDestroy($this->_imgOrig);
@ImageDestroy($this->_imgFinal);
$this->_imgOrig = $this->_imgFinal = null;
}
/**
* @return bool
* @param int $ox Original image width
* @param int $oy Original image height
* @param int $nx New width
* @param int $ny New height
* @param int $position Where to place the crop
* @param string $function Name of the calling function
* @desc Creates the cropped image based on passed parameters
*/
function _cropSize($ox, $oy, $nx, $ny, $position, $function)
{
if ($this->_imgOrig == null)
{
$this->_debug($function, 'The original image has not been loaded.');
return false;
}
if (($nx <= 0) || ($ny <= 0))
{
$this->_debug($function, 'The image could not be cropped because the size given is not valid.');
return false;
}
if (($nx > @ImageSX($this->_imgOrig)) || ($ny > @ImageSY($this->_imgOrig)))
{
$this->_debug($function, 'The image could not be cropped because the size given is larger than the original image.');
return false;
}
if ($ox == -1 || $oy == -1)
{
list($ox, $oy) = $this->_getCopyPosition($nx, $ny, $position);
}
if ($this->_gdVersion == 2)
{
$this->_imgFinal = @ImageCreateTrueColor($nx, $ny);
@ImageCopyResampled($this->_imgFinal, $this->_imgOrig, 0, 0, $ox, $oy, $nx, $ny, $nx, $ny);
}
else
{
$this->_imgFinal = @ImageCreate($nx, $ny);
@ImageCopyResized($this->_imgFinal, $this->_imgOrig, 0, 0, $ox, $oy, $nx, $ny, $nx, $ny);
}
return true;
}
/**
* @return array
* @param int $nx
* @param int $ny
* @param int $position
* @desc Determines dimensions of the crop
*/
function _getCopyPosition($nx, $ny, $position)
{
$ox = @ImageSX($this->_imgOrig);
$oy = @ImageSY($this->_imgOrig);
switch($position)
{
case ccTOPLEFT:
return array(0, 0);
case ccTOP:
return array(ceil(($ox - $nx) / 2), 0);
case ccTOPRIGHT:
return array(($ox - $nx), 0);
case ccLEFT:
return array(0, ceil(($oy - $ny) / 2));
case ccCENTRE:
return array(ceil(($ox - $nx) / 2), ceil(($oy - $ny) / 2));
case ccRIGHT:
return array(($ox - $nx), ceil(($oy - $ny) / 2));
case ccBOTTOMLEFT:
return array(0, ($oy - $ny));
case ccBOTTOM:
return array(ceil(($ox - $nx) / 2), ($oy - $ny));
case ccBOTTOMRIGHT:
return array(($ox - $nx), ($oy - $ny));
}
}
/**
* @return float
* @param resource $im
* @param int $x
* @param int $y
* @desc Determines the intensity value of a pixel at the passed co-ordinates
*/
function _getThresholdValue($im, $x, $y)
{
$rgb = ImageColorAt($im, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
$intensity = ($r + $g + $b) / 3;
return $intensity;
}
/**
* @return string
* @param string $filename
* @desc Get the extension of a file name
*/
function _getExtension($filename)
{
$ext = @strtolower(@substr($filename, (@strrpos($filename, ".") ? @strrpos($filename, ".") + 1 : @strlen($filename)), @strlen($filename)));
return ($ext == 'jpg') ? 'jpeg' : $ext;
}
/**
* @return void
* @param string $function
* @param string $string
* @desc Shows debugging information
*/
function _debug($function, $string)
{
if ($this->_showDebug)
{
echo "<p><strong style=\"color:#FF0000\">Error in function $function:</strong> $string</p>\n";
}
}
/**
* @return array
* @desc Try to ascertain what the version of GD being used is, based on phpinfo output
*/
function _getGDVersion()
{
static $version = array();
if (empty($version))
{
ob_start();
phpinfo();
$buffer = ob_get_contents();
ob_end_clean();
if (preg_match("|<B>GD Version</B></td><TD ALIGN=\"left\">([^<]*)</td>|i", $buffer, $matches))
{
$version = explode('.', $matches[1]);
}
else if (preg_match("|GD Version </td><td class=\"v\">bundled \(([^ ]*)|i", $buffer, $matches))
{
$version = explode('.', $matches[1]);
}
else if (preg_match("|GD Version </td><td class=\"v\">([^ ]*)|i", $buffer, $matches))
{
$version = explode('.', $matches[1]);
}
}
return $version;
}
}
?>
| DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware. |
More GUI Code Articles
More By Codewalkers
 developerWorks - FREE Tools!
|
This demonstration gives you an overview of IBM® Rational® Build Forge Express Edition, a global offering that provides a framework to automate and execute software processes. Rational Build Forge provides a software assembly line that can support all of your tools, technologies, and platforms so you can achieve a repeatable, reliable, and traceable build and release process.
FREE! Go There Now!
|
|
|
|
Visit IBM developerWorks to download a free trial version of Lotus Quickr 8.0, which enables collaboration by transforming the way everyday business content such as documents, rich media, photos, and video can be shared. Lotus Quickr makes it faster and easier to share content of all types (not just documents) within virtual teams. It is designed to make it easier to collaborate across organizational boundaries, while continuing to work within the context of familiar desktop applications.
FREE! Go There Now!
|
|
|
|
Download a free trial version of IBM Rational Developer for System i V7.1, which provides a complete development environment for traditional i5/OS application development. IBM Rational Developer for System i is a new eclipse-based workstation offering for i5/OS application development that provides a comprehensive Integrated Development Environment for edit/compile/debug of traditional RPG/COBOL/C/C++ i5/OS applications.
FREE! Go There Now!
|
|
|
|
Visit IBM developerWorks to download a free trial version of WebSphere Extended Deployment Compute Grid, which lets you schedule, execute, and monitor batch jobs. Because online transaction processing and batch jobs execute simultaneously on the same server resources, you can avoid costly duplication of resources. Compute Grid supports job types of Java transactional batch, compute-intensive and a new type called "native execution", which enables non-Java workloads to run on distributed end points.
FREE! Go There Now!
|
|
|
|
Secure your Web applications with IBM Rational AppScan Standard Edition V7.7, previously known as Watchfire AppScan. This Web application security testing tool automates vulnerability assessments and scans and tests for common Web application vulnerabilities. Visit IBM developerWorks to download a free trial of IBM Rational AppScan Standard Edition V7.7.
FREE! Go There Now!
|
|
|
|
Learn how Rational Build Forge can extend a simple compile and package build process by adding customization and deployment capability. Go from a manual method to automating: checking for code changes; getting the latest source; compiling and packaging; customizing; copying to and restarting a deployment server; and sending e-mail notification that a new version is available.
FREE! Go There Now!
|
|
|
|
Portfolio Management is about effectively managing portfolio value by aligning portfolio investments with business goals. This complimentary e-kit provides a collection of materials that can help you understand how IBM Rational enables and automates best practices for improved governance and clear visibility into portfolio and project performance across the entire IT project lifecycle.
FREE! Go There Now!
|
|
|
|
Join this Rational Talks to You teleconference on December 6 at 1:00 pm ET to participate in an agile application development discussion and get your questions answered on using IBM Rational Method Composer in a distributed environment.Get your questions answered!
FREE! Go There Now!
|
|
|
|
Get a free trial download of the latest version of IBM Rational Functional Tester V7.0.1. Rational Functional Tester is an automated functional and regression testing solution for QA teams concerned with the quality of their Java, Microsoft Visual Studio .NET, and Web-based applications.
FREE! Go There Now!
|
|
|
|
Join the IBM Watchfire team for an informative discussion on techniques and best practices to proactively manage Web application security and how to effectively build application security testing into the software development lifecycle (SDLC). In this Software Delivery Platform webcast you will learn: How to better understand potential web application security vulnerabilities, best practices and how to effectively integrate application security testing into the software development lifecycle, the importance of detecting and removing software vulnerabilities during application development.
FREE! Go There Now!
|
|
|
|
All FREE IBM® developerWorks Tools!
|
