/home/edulekha/studygroup.edulekha.com/ow_libraries/wideimage/Image.php
<?php
/**
* @author Gasper Kozak
* @copyright 2007-2011
This file is part of WideImage.
WideImage is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
WideImage is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with WideImage; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
* @package WideImage
**/
/**
* Thrown when an invalid dimension is passed for some operations
*
* @package Exceptions
*/
class WideImage_InvalidImageDimensionException extends WideImage_Exception {}
/**
* Thrown when an image can't be saved (returns false by the mapper)
*
* @package Exceptions
*/
class WideImage_UnknownErrorWhileMappingException extends WideImage_Exception {}
/**
* Base class for images
*
* @package WideImage
*/
abstract class WideImage_Image
{
/**
* Holds the image resource
* @var resource
*/
protected $handle = null;
/**
* Flag that determines if WideImage should call imagedestroy() upon object destruction
* @var bool
*/
protected $handleReleased = false;
/**
* Canvas object
* @var WideImage_Canvas
*/
protected $canvas = null;
/**
* @var string
*/
protected $sdata = null;
/**
* The base class constructor
*
* @param resource $handle Image handle (GD2 resource)
*/
function __construct($handle)
{
WideImage::assertValidImageHandle($handle);
$this->handle = $handle;
}
/**
* Cleanup
*
* Destroys the handle via WideImage_Image::destroy() when called by the GC.
*/
function __destruct()
{
$this->destroy();
}
/**
* This method destroy the image handle, and releases the image resource.
*
* After this is called, the object doesn't hold a valid image any more.
* No operation should be called after that.
*/
function destroy()
{
if ($this->isValid() && !$this->handleReleased)
imagedestroy($this->handle);
$this->handle = null;
}
/**
* Returns the GD image resource
*
* @return resource GD image resource
*/
function getHandle()
{
return $this->handle;
}
/**
* @return bool True, if the image object holds a valid GD image, false otherwise
*/
function isValid()
{
return WideImage::isValidImageHandle($this->handle);
}
/**
* Releases the handle
*/
function releaseHandle()
{
$this->handleReleased = true;
}
/**
* Saves an image to a file
*
* The file type is recognized from the $uri. If you save to a GIF8, truecolor images
* are automatically converted to palette.
*
* This method supports additional parameters: quality (for jpeg images) and
* compression quality and filters (for png images). See http://www.php.net/imagejpeg and
* http://www.php.net/imagepng for details.
*
* Examples:
* <code>
* // save to a GIF
* $image->saveToFile('image.gif');
*
* // save to a PNG with compression=7 and no filters
* $image->saveToFile('image.png', 7, PNG_NO_FILTER);
*
* // save to a JPEG with quality=80
* $image->saveToFile('image.jpg', 80);
*
* // save to a JPEG with default quality=100
* $image->saveToFile('image.jpg');
* </code>
*
* @param string $uri File location
*/
function saveToFile($uri)
{
$mapper = WideImage_MapperFactory::selectMapper($uri, null);
$args = func_get_args();
array_unshift($args, $this->getHandle());
$res = call_user_func_array(array($mapper, 'save'), $args);
if (!$res)
throw new WideImage_UnknownErrorWhileMappingException(get_class($mapper) . " returned an invalid result while saving to $uri");
}
/**
* Returns binary string with image data in format specified by $format
*
* Additional parameters may be passed to the function. See WideImage_Image::saveToFile() for more details.
*
* @param string $format The format of the image
* @return string The binary image data in specified format
*/
function asString($format)
{
ob_start();
$args = func_get_args();
$args[0] = null;
array_unshift($args, $this->getHandle());
$mapper = WideImage_MapperFactory::selectMapper(null, $format);
$res = call_user_func_array(array($mapper, 'save'), $args);
if (!$res)
throw new WideImage_UnknownErrorWhileMappingException(get_class($mapper) . " returned an invalid result while writing the image data");
return ob_get_clean();
}
/**
* Output a header to browser.
*
* @param $name Name of the header
* @param $data Data
*/
protected function writeHeader($name, $data)
{
header($name . ": " . $data);
}
/**
* Outputs the image to browser
*
* Sets headers Content-length and Content-type, and echoes the image in the specified format.
* All other headers (such as Content-disposition) must be added manually.
*
* Example:
* <code>
* WideImage::load('image1.png')->resize(100, 100)->output('gif');
* </code>
*
* @param string $format Image format
*/
function output($format)
{
$args = func_get_args();
$data = call_user_func_array(array($this, 'asString'), $args);
$this->writeHeader('Content-length', strlen($data));
$this->writeHeader('Content-type', WideImage_MapperFactory::mimeType($format));
echo $data;
}
/**
* @return int Image width
*/
function getWidth()
{
return imagesx($this->handle);
}
/**
* @return int Image height
*/
function getHeight()
{
return imagesy($this->handle);
}
/**
* Allocate a color by RGB values.
*
* @param mixed $R Red-component value or an RGB array (with red, green, blue keys)
* @param int $G If $R is int, this is the green component
* @param int $B If $R is int, this is the blue component
* @return int Image color index
*/
function allocateColor($R, $G = null, $B = null)
{
if (is_array($R))
return imageColorAllocate($this->handle, $R['red'], $R['green'], $R['blue']);
else
return imageColorAllocate($this->handle, $R, $G, $B);
}
/**
* @return bool True if the image is transparent, false otherwise
*/
function isTransparent()
{
return $this->getTransparentColor() >= 0;
}
/**
* @return int Transparent color index
*/
function getTransparentColor()
{
return imagecolortransparent($this->handle);
}
/**
* Sets the current transparent color index. Only makes sense for palette images (8-bit).
*
* @param int $color Transparent color index
*/
function setTransparentColor($color)
{
return imagecolortransparent($this->handle, $color);
}
/**
* Returns a RGB array of the transparent color or null if none.
*
* @return mixed Transparent color RGBA array
*/
function getTransparentColorRGB()
{
$total = imagecolorstotal($this->handle);
$tc = $this->getTransparentColor();
if ($tc >= $total && $total > 0)
return null;
else
return $this->getColorRGB($tc);
}
/**
* Returns a RGBA array for pixel at $x, $y
*
* @param int $x
* @param int $y
* @return array RGB array
*/
function getRGBAt($x, $y)
{
return $this->getColorRGB($this->getColorAt($x, $y));
}
/**
* Writes a pixel at the designated coordinates
*
* Takes an associative array of colours and uses getExactColor() to
* retrieve the exact index color to write to the image with.
*
* @param int $x
* @param int $y
* @param array $color
*/
function setRGBAt($x, $y, $color)
{
$this->setColorAt($x, $y, $this->getExactColor($color));
}
/**
* Returns a color's RGB
*
* @param int $colorIndex Color index
* @return mixed RGBA array for a color with index $colorIndex
*/
function getColorRGB($colorIndex)
{
return imageColorsForIndex($this->handle, $colorIndex);
}
/**
* Returns an index of the color at $x, $y
*
* @param int $x
* @param int $y
* @return int Color index for a pixel at $x, $y
*/
function getColorAt($x, $y)
{
return imagecolorat($this->handle, $x, $y);
}
/**
* Set the color index $color to a pixel at $x, $y
*
* @param int $x
* @param int $y
* @param int $color Color index
*/
function setColorAt($x, $y, $color)
{
return imagesetpixel($this->handle, $x, $y, $color);
}
/**
* Returns closest color index that matches the given RGB value. Uses
* PHP's imagecolorclosest()
*
* @param mixed $R Red or RGBA array
* @param int $G Green component (or null if $R is an RGB array)
* @param int $B Blue component (or null if $R is an RGB array)
* @return int Color index
*/
function getClosestColor($R, $G = null, $B = null)
{
if (is_array($R))
return imagecolorclosest($this->handle, $R['red'], $R['green'], $R['blue']);
else
return imagecolorclosest($this->handle, $R, $G, $B);
}
/**
* Returns the color index that exactly matches the given RGB value. Uses
* PHP's imagecolorexact()
*
* @param mixed $R Red or RGBA array
* @param int $G Green component (or null if $R is an RGB array)
* @param int $B Blue component (or null if $R is an RGB array)
* @return int Color index
*/
function getExactColor($R, $G = null, $B = null)
{
if (is_array($R))
return imagecolorexact($this->handle, $R['red'], $R['green'], $R['blue']);
else
return imagecolorexact($this->handle, $R, $G, $B);
}
/**
* Copies transparency information from $sourceImage. Optionally fills
* the image with the transparent color at (0, 0).
*
* @param object $sourceImage
* @param bool $fill True if you want to fill the image with transparent color
*/
function copyTransparencyFrom($sourceImage, $fill = true)
{
if ($sourceImage->isTransparent())
{
$rgba = $sourceImage->getTransparentColorRGB();
if ($rgba === null)
return;
if ($this->isTrueColor())
{
$rgba['alpha'] = 127;
$color = $this->allocateColorAlpha($rgba);
}
else
$color = $this->allocateColor($rgba);
$this->setTransparentColor($color);
if ($fill)
$this->fill(0, 0, $color);
}
}
/**
* Fill the image at ($x, $y) with color index $color
*
* @param int $x
* @param int $y
* @param int $color
*/
function fill($x, $y, $color)
{
return imagefill($this->handle, $x, $y, $color);
}
/**
* Used internally to create Operation objects
*
* @param string $name
* @return object
*/
protected function getOperation($name)
{
return WideImage_OperationFactory::get($name);
}
/**
* Returns the image's mask
*
* Mask is a greyscale image where the shade defines the alpha channel (black = transparent, white = opaque).
*
* For opaque images (JPEG), the result will be white. For images with single-color transparency (GIF, 8-bit PNG),
* the areas with the transparent color will be black. For images with alpha channel transparenct,
* the result will be alpha channel.
*
* @return WideImage_Image An image mask
**/
function getMask()
{
return $this->getOperation('GetMask')->execute($this);
}
/**
* Resize the image to given dimensions.
*
* $width and $height are both smart coordinates. This means that you can pass any of these values in:
* - positive or negative integer (100, -20, ...)
* - positive or negative percent string (30%, -15%, ...)
* - complex coordinate (50% - 20, 15 + 30%, ...)
*
* If $width is null, it's calculated proportionally from $height, and vice versa.
*
* Example (resize to half-size):
* <code>
* $smaller = $image->resize('50%');
*
* $smaller = $image->resize('100', '100', 'inside', 'down');
* is the same as
* $smaller = $image->resizeDown(100, 100, 'inside');
* </code>
*
* @param mixed $width The new width (smart coordinate), or null.
* @param mixed $height The new height (smart coordinate), or null.
* @param string $fit 'inside', 'outside', 'fill'
* @param string $scale 'down', 'up', 'any'
* @return WideImage_Image The resized image
*/
function resize($width = null, $height = null, $fit = 'inside', $scale = 'any')
{
return $this->getOperation('Resize')->execute($this, $width, $height, $fit, $scale);
}
/**
* Same as WideImage_Image::resize(), but the image is only applied if it is larger then the given dimensions.
* Otherwise, the resulting image retains the source's dimensions.
*
* @param int $width New width, smart coordinate
* @param int $height New height, smart coordinate
* @param string $fit 'inside', 'outside', 'fill'
* @return WideImage_Image resized image
*/
function resizeDown($width = null, $height = null, $fit = 'inside')
{
return $this->resize($width, $height, $fit, 'down');
}
/**
* Same as WideImage_Image::resize(), but the image is only applied if it is smaller then the given dimensions.
* Otherwise, the resulting image retains the source's dimensions.
*
* @param int $width New width, smart coordinate
* @param int $height New height, smart coordinate
* @param string $fit 'inside', 'outside', 'fill'
* @return WideImage_Image resized image
*/
function resizeUp($width = null, $height = null, $fit = 'inside')
{
return $this->resize($width, $height, $fit, 'up');
}
/**
* Rotate the image for angle $angle clockwise.
*
* Preserves transparency. Has issues when saving to a BMP.
*
* @param int $angle Angle in degrees, clock-wise
* @param int $bgColor color of the new background
* @param bool $ignoreTransparent
* @return WideImage_Image The rotated image
*/
function rotate($angle, $bgColor = null, $ignoreTransparent = true)
{
return $this->getOperation('Rotate')->execute($this, $angle, $bgColor, $ignoreTransparent);
}
/**
* This method lays the overlay (watermark) on the image.
*
* Hint: if the overlay is a truecolor image with alpha channel, you should leave $pct at 100.
*
* This operation supports alignment notation in coordinates:
* <code>
* $watermark = WideImage::load('logo.gif');
* $base = WideImage::load('picture.jpg');
* $result = $base->merge($watermark, "right - 10", "bottom - 10", 50);
* // applies a logo aligned to bottom-right corner with a 10 pixel margin
* </code>
*
* @param WideImage_Image $overlay The overlay image
* @param mixed $left Left position of the overlay, smart coordinate
* @param mixed $top Top position of the overlay, smart coordinate
* @param int $pct The opacity of the overlay
* @return WideImage_Image The merged image
*/
function merge($overlay, $left = 0, $top = 0, $pct = 100)
{
return $this->getOperation('Merge')->execute($this, $overlay, $left, $top, $pct);
}
/**
* Resizes the canvas of the image, but doesn't scale the content of the image
*
* This operation creates an empty canvas with dimensions $width x $height, filled with
* background color $bg_color and draws the original image onto it at position [$pos_x, $pos_y].
*
* Arguments $width, $height, $pos_x and $pos_y are all smart coordinates. $width and $height are
* relative to the current image size, $pos_x and $pos_y are relative to the newly calculated
* canvas size. This can be confusing, but it makes sense. See the example below.
*
* The example below loads a 100x150 image and then resizes its canvas to 200% x 100%+20
* (which evaluates to 200x170). The image is placed at position [10, center+20], which evaluates to [10, 30].
* <code>
* $image = WideImage::load('someimage.jpg'); // 100x150
* $white = $image->allocateColor(255, 255, 255);
* $image->resizeCanvas('200%', '100% + 20', 10, 'center+20', $white);
* </code>
*
* The parameter $merge defines whether the original image should be merged onto the new canvas.
* This means it blends transparent color and alpha colors into the background color. If set to false,
* the original image is just copied over, preserving the transparency/alpha information.
*
* You can set the $scale parameter to limit when to resize the canvas. For example, if you want
* to resize the canvas only if the image is smaller than the new size, but leave the image intact
* if it's larger, set it to 'up'. Likewise, if you want to shrink the canvas, but don't want to
* change images that are already smaller, set it to 'down'.
*
* @param mixed $width Width of the new canvas (smart coordinate, relative to current image width)
* @param mixed $height Height of the new canvas (smart coordinate, relative to current image height)
* @param mixed $pos_x x-position of the image (smart coordinate, relative to the new width)
* @param mixed $pos_y y-position of the image (smart coordinate, relative to the new height)
* @param int $bg_color Background color (created with allocateColor or allocateColorAlpha), defaults to null (tries to use a transparent color)
* @param string $scale Possible values: 'up' (enlarge only), 'down' (downsize only), 'any' (resize precisely to $width x $height). Defaults to 'any'.
* @param bool $merge Merge the original image (flatten alpha channel and transparency) or copy it over (preserve). Defaults to false.
* @return WideImage_Image The resulting image with resized canvas
*/
function resizeCanvas($width, $height, $pos_x, $pos_y, $bg_color = null, $scale = 'any', $merge = false)
{
return $this->getOperation('ResizeCanvas')->execute($this, $width, $height, $pos_x, $pos_y, $bg_color, $scale, $merge);
}
/**
* Returns an image with round corners
*
* You can either set the corners' color or set them transparent.
*
* Note on $smoothness: 1 means jagged edges, 2 is much better, more than 4 doesn't noticeably improve the quality.
* Rendering becomes increasingly slower if you increase smoothness.
*
* Example:
* <code>
* $nice = $ugly->roundCorners(20, $ugly->allocateColor(255, 0, 0), 2);
* </code>
*
* Use $corners parameter to specify which corners to draw rounded. Possible values are
* WideImage::SIDE_TOP_LEFT, WideImage::SIDE_TOP,
* WideImage::SIDE_TOP_RIGHT, WideImage::SIDE_RIGHT,
* WideImage::SIDE_BOTTOM_RIGHT, WideImage::SIDE_BOTTOM,
* WideImage::SIDE_BOTTOM_LEFT, WideImage::SIDE_LEFT, and WideImage::SIDE_ALL.
* You can specify any combination of corners with a + operation, see example below.
*
* Example:
* <code>
* $white = $image->allocateColor(255, 255, 255);
* $diagonal_corners = $image->roundCorners(15, $white, 2, WideImage::SIDE_TOP_LEFT + WideImage::SIDE_BOTTOM_RIGHT);
* $right_corners = $image->roundCorners(15, $white, 2, WideImage::SIDE_RIGHT);
* </code>
*
* @param int $radius Radius of the corners
* @param int $color The color of corners. If null, corners are rendered transparent (slower than using a solid color).
* @param int $smoothness Specify the level of smoothness. Suggested values from 1 to 4.
* @param int $corners Specify which corners to draw (defaults to WideImage::SIDE_ALL = all corners)
* @return WideImage_Image The resulting image with round corners
*/
function roundCorners($radius, $color = null, $smoothness = 2, $corners = 255)
{
return $this->getOperation('RoundCorners')->execute($this, $radius, $color, $smoothness, $corners);
}
/**
* Returns an image with applied mask
*
* A mask is a grayscale image, where the shade determines the alpha channel. Black is fully transparent
* and white is fully opaque.
*
* @param WideImage_Image $mask The mask image, greyscale
* @param mixed $left Left coordinate, smart coordinate
* @param mixed $top Top coordinate, smart coordinate
* @return WideImage_Image The resulting image
**/
function applyMask($mask, $left = 0, $top = 0)
{
return $this->getOperation('ApplyMask')->execute($this, $mask, $left, $top);
}
/**
* Applies a filter
*
* @param int $filter One of the IMG_FILTER_* constants
* @param int $arg1
* @param int $arg2
* @param int $arg3
* @param int $arg4
* @return WideImage_Image
*/
function applyFilter($filter, $arg1 = null, $arg2 = null, $arg3 = null, $arg4 = null)
{
return $this->getOperation('ApplyFilter')->execute($this, $filter, $arg1, $arg2, $arg3, $arg4);
}
/**
* Applies convolution matrix with imageconvolution()
*
* @param array $matrix
* @param float $div
* @param float $offset
* @return WideImage_Image
*/
function applyConvolution($matrix, $div, $offset)
{
return $this->getOperation('ApplyConvolution')->execute($this, $matrix, $div, $offset);
}
/**
* Returns a cropped rectangular portion of the image
*
* If the rectangle specifies area that is out of bounds, it's limited to the current image bounds.
*
* Examples:
* <code>
* $cropped = $img->crop(10, 10, 150, 200); // crops a 150x200 rect at (10, 10)
* $cropped = $img->crop(-100, -50, 100, 50); // crops a 100x50 rect at the right-bottom of the image
* $cropped = $img->crop('25%', '25%', '50%', '50%'); // crops a 50%x50% rect from the center of the image
* </code>
*
* This operation supports alignment notation in left/top coordinates.
* Example:
* <code>
* $cropped = $img->crop("right", "bottom", 100, 200); // crops a 100x200 rect from right bottom
* $cropped = $img->crop("center", "middle", 50, 30); // crops a 50x30 from the center of the image
* </code>
*
* @param mixed $left Left-coordinate of the crop rect, smart coordinate
* @param mixed $top Top-coordinate of the crop rect, smart coordinate
* @param mixed $width Width of the crop rect, smart coordinate
* @param mixed $height Height of the crop rect, smart coordinate
* @return WideImage_Image The cropped image
**/
function crop($left = 0, $top = 0, $width = '100%', $height = '100%')
{
return $this->getOperation('Crop')->execute($this, $left, $top, $width, $height);
}
/**
* Performs an auto-crop on the image
*
* The image is auto-cropped from each of four sides. All sides are
* scanned for pixels that differ from $base_color for more than
* $rgb_threshold in absolute RGB difference. If more than $pixel_cutoff
* differentiating pixels are found, that line is considered to be the crop line for the side.
* If the line isn't different enough, the algorithm procedes to the next line
* towards the other edge of the image.
*
* When the crop rectangle is found, it's enlarged by the $margin value on each of the four sides.
*
* @param int $margin Margin for the crop rectangle, can be negative.
* @param int $rgb_threshold RGB difference which still counts as "same color".
* @param int $pixel_cutoff How many pixels need to be different to mark a cut line.
* @param int $base_color The base color index. If none specified (or null given), left-top pixel is used.
* @return WideImage_Image The cropped image
*/
function autoCrop($margin = 0, $rgb_threshold = 0, $pixel_cutoff = 1, $base_color = null)
{
return $this->getOperation('AutoCrop')->execute($this, $margin, $rgb_threshold, $pixel_cutoff, $base_color);
}
/**
* Returns a negative of the image
*
* This operation differs from calling WideImage_Image::applyFilter(IMG_FILTER_NEGATIVE), because it's 8-bit and transparency safe.
* This means it will return an 8-bit image, if the source image is 8-bit. If that 8-bit image has a palette transparency,
* the resulting image will keep transparency.
*
* @return WideImage_Image negative of the image
*/
function asNegative()
{
return $this->getOperation('AsNegative')->execute($this);
}
/**
* Returns a grayscale copy of the image
*
* @return WideImage_Image grayscale copy
**/
function asGrayscale()
{
return $this->getOperation('AsGrayscale')->execute($this);
}
/**
* Returns a mirrored copy of the image
*
* @return WideImage_Image Mirrored copy
**/
function mirror()
{
return $this->getOperation('Mirror')->execute($this);
}
/**
* Applies the unsharp filter
*
* @param float $amount
* @param float $radius
* @param float $threshold
* @return WideImage_Image Unsharpened copy of the image
**/
function unsharp($amount, $radius, $threshold)
{
return $this->getOperation('Unsharp')->execute($this, $amount, $radius, $threshold);
}
/**
* Returns a flipped (mirrored over horizontal line) copy of the image
*
* @return WideImage_Image Flipped copy
**/
function flip()
{
return $this->getOperation('Flip')->execute($this);
}
/**
* Corrects gamma on the image
*
* @param float $inputGamma
* @param float $outputGamma
* @return WideImage_Image Image with corrected gamma
**/
function correctGamma($inputGamma, $outputGamma)
{
return $this->getOperation('CorrectGamma')->execute($this, $inputGamma, $outputGamma);
}
/**
* Adds noise to the image
*
* @author Tomasz Kapusta
*
* @param int $amount Number of noise pixels to add
* @param string $type Type of noise 'salt&pepper', 'color' or 'mono'
* @return WideImage_Image Image with noise added
**/
function addNoise($amount, $type)
{
return $this->getOperation('AddNoise')->execute($this, $amount, $type);
}
/**
* Used internally to execute operations
*
* @param string $name
* @param array $args
* @return WideImage_Image
*/
function __call($name, $args)
{
$op = $this->getOperation($name);
array_unshift($args, $this);
return call_user_func_array(array($op, 'execute'), $args);
}
/**
* Returns an image in GIF or PNG format
*
* @return string
*/
function __toString()
{
if ($this->isTransparent())
return $this->asString('gif');
else
return $this->asString('png');
}
/**
* Returns a copy of the image object
*
* @return WideImage_Image The copy
**/
function copy()
{
$dest = $this->doCreate($this->getWidth(), $this->getHeight());
$dest->copyTransparencyFrom($this, true);
$this->copyTo($dest, 0, 0);
return $dest;
}
/**
* Copies this image onto another image
*
* @param WideImage_Image $dest
* @param int $left
* @param int $top
**/
function copyTo($dest, $left = 0, $top = 0)
{
if (!imagecopy($dest->getHandle(), $this->handle, $left, $top, 0, 0, $this->getWidth(), $this->getHeight()))
throw new WideImage_GDFunctionResultException("imagecopy() returned false");
}
/**
* Returns the canvas object
*
* The Canvas object can be used to draw text and shapes on the image
*
* Examples:
* <code>
* $img = WideImage::load('pic.jpg);
* $canvas = $img->getCanvas();
* $canvas->useFont('arial.ttf', 15, $img->allocateColor(200, 220, 255));
* $canvas->writeText(10, 50, "Hello world!");
*
* $canvas->filledRectangle(10, 10, 80, 40, $img->allocateColor(255, 127, 255));
* $canvas->line(60, 80, 30, 100, $img->allocateColor(255, 0, 0));
* $img->saveToFile('new.png');
* </code>
*
* @return WideImage_Canvas The Canvas object
**/
function getCanvas()
{
if ($this->canvas == null)
$this->canvas = new WideImage_Canvas($this);
return $this->canvas;
}
/**
* Returns true if the image is true-color, false otherwise
*
* @return bool
**/
abstract function isTrueColor();
/**
* Returns a true-color copy of the image
*
* @return WideImage_TrueColorImage
**/
abstract function asTrueColor();
/**
* Returns a palette copy (8bit) of the image
*
* @param int $nColors Number of colors in the resulting image, more than 0, less or equal to 255
* @param bool $dither Use dithering or not
* @param bool $matchPalette Set to true to use imagecolormatch() to match the resulting palette more closely to the original image
* @return WideImage_Image
**/
abstract function asPalette($nColors = 255, $dither = null, $matchPalette = true);
/**
* Retrieve an image with selected channels
*
* Examples:
* <code>
* $channels = $img->getChannels('red', 'blue');
* $channels = $img->getChannels('alpha', 'green');
* $channels = $img->getChannels(array('green', 'blue'));
* </code>
*
* @return WideImage_Image
**/
abstract function getChannels();
/**
* Returns an image without an alpha channel
*
* @return WideImage_Image
**/
abstract function copyNoAlpha();
/**
* Returns an array of serializable protected variables. Called automatically upon serialize().
*
* @return array
*/
function __sleep()
{
$this->sdata = $this->asString('png');
return array('sdata', 'handleReleased');
}
/**
* Restores an image from serialization. Called automatically upon unserialize().
*/
function __wakeup()
{
$temp_image = WideImage::loadFromString($this->sdata);
$temp_image->releaseHandle();
$this->handle = $temp_image->handle;
$temp_image = null;
$this->sdata = null;
}
}