Mike42\Escpos\EscposImage Class Reference

This class deals with images in raster formats, and converts them into formats which are suitable for use on thermal receipt printers. More...

Inheritance diagram for Mike42\Escpos\EscposImage:

Public Member Functions
	__construct ($filename=null, $allowOptimisations=true)
	Construct a new EscposImage. More...
	getHeight ()
	getHeightBytes ()
	getWidth ()
	getWidthBytes ()
	toRasterFormat ()
	Output the image in raster (row) format. More...
	toColumnFormat ($doubleDensity=false)
	Output the image in column format. More...

Static Public Member Functions
static	isGdLoaded ()
static	isImagickLoaded ()
static	load (string $filename, bool $allowOptimisations=true, array $preferred=['imagick', 'gd', 'native'])
	This is a convinience method to load an image from file, auto-selecting an EscposImage implementation which uses an available library. More...

Protected Member Functions
	loadImageData (string $filename=null)
	Load an image from disk. More...
	setImgData ($data)
	Set image data. More...
	setImgWidth ($width)
	Set image width. More...
	setImgHeight ($height)
	Set image height. More...
	getRasterFormatFromFile ($filename=null)
	getColumnFormatFromFile ($filename=null, $highDensityVertical=true)

Protected Attributes
	$imgHeight = 0
	height of the image.
	$imgWidth = 0
	width of the image

Detailed Description

This class deals with images in raster formats, and converts them into formats which are suitable for use on thermal receipt printers.

Currently, only PNG images (in) and ESC/POS raster format (out) are implemeted.

Input formats:

• Currently, only PNG is supported.
• Other easily read raster formats (jpg, gif) will be added at a later date, as this is not complex.
• The BMP format can be directly read by some commands, but this has not yet been implemented.

Output formats:

• Currently, only ESC/POS raster format is supported
• ESC/POS 'column format' support is partially implemented, but is not yet used by Escpos.php library.
• Output as multiple rows of column format image is not yet in the works.

Libraries:

• Currently, php-gd is used to read the input. Support for imagemagick where gd is not installed is also not complex to add, and is a likely future feature.
• Support for native use of the BMP format is a goal, for maximum compatibility with target environments.

Constructor & Destructor Documentation

__construct()

Mike42\Escpos\EscposImage::__construct	(		$filename = null,
			$allowOptimisations = true
	)

Construct a new EscposImage.

Parameters

string	$filename	Path to image filename, or null to create an empty image.
boolean	$allowOptimisations	True (default) to use any library-specific tricks to speed up rendering, false to force the image to be read in pixel-by-pixel, which is easier to unit test and more reproducible between systems, but slower.

Member Function Documentation

getColumnFormatFromFile()

Mike42\Escpos\EscposImage::getColumnFormatFromFile (   $filename = null,   $highDensityVertical = true  )

protected

Parameters

string	$filename	Filename to load from
boolean	$highDensityVertical	True for high density output (24px lines), false for regular density (8px)

Returns

string[]|NULL Column format data as array, or NULL if optimised renderer isn't available in this implementation.

getHeight()

Mike42\Escpos\EscposImage::getHeight

(

)

Returns

int height of the image in pixels

getHeightBytes()

Mike42\Escpos\EscposImage::getHeightBytes

(

)

Returns

int Number of bytes to represent a row of this image

getRasterFormatFromFile()

Mike42\Escpos\EscposImage::getRasterFormatFromFile (   $filename = null )

protected

Parameters

string

$filename

Filename to load from

Returns

string|NULL Raster format data, or NULL if no optimised renderer is available in this implementation.

getWidth()

Mike42\Escpos\EscposImage::getWidth

(

)

Returns

int Width of the image

getWidthBytes()

Mike42\Escpos\EscposImage::getWidthBytes

(

)

Returns

int Number of bytes to represent a row of this image

isGdLoaded()

static Mike42\Escpos\EscposImage::isGdLoaded ( )

static

Returns

boolean True if GD is loaded, false otherwise

isImagickLoaded()

static Mike42\Escpos\EscposImage::isImagickLoaded ( )

static

Returns

boolean True if Imagick is loaded, false otherwise

load()

static Mike42\Escpos\EscposImage::load ( string  $filename, bool  $allowOptimisations = true, array  $preferred = ['imagick', 'gd'  , 'native']    )

static

This is a convinience method to load an image from file, auto-selecting an EscposImage implementation which uses an available library.

The sub-classes can be constructed directly if you know that you will have Imagick or GD on the print server.

Parameters

string	$filename	File to load from
bool	$allowOptimisations	True to allow the fastest rendering shortcuts, false to force the library to read the image into an internal raster format and use PHP to render the image (slower but less fragile).
array	$preferred	Order to try to load libraries in- escpos-php supports pluggable image libraries. Items can be 'imagick', 'gd', 'native'.

Exceptions

Exception

Where no suitable library could be found for the type of file being loaded.

Returns

EscposImage

loadImageData()

Mike42\Escpos\EscposImage::loadImageData ( string  $filename = null )

protected

Load an image from disk.

This default implementation always gives a zero-sized image.

Parameters

string | null

$filename

Filename to load from.

setImgData()

Mike42\Escpos\EscposImage::setImgData (   $data )

protected

Set image data.

Parameters

string

$data

Image data to use, string of 1's (black) and 0's (white) in row-major order.

setImgHeight()

Mike42\Escpos\EscposImage::setImgHeight (   $height )

protected

Set image height.

Parameters

int

$height

height of the image.

setImgWidth()

Mike42\Escpos\EscposImage::setImgWidth (   $width )

protected

Set image width.

Parameters

int

$width

width of the image

toColumnFormat()

Mike42\Escpos\EscposImage::toColumnFormat

(

$doubleDensity = false

)

Output the image in column format.

Parameters

boolean

$doubleDensity

True for double density (24px) lines, false for single-density (8px) lines.

Returns

string[] an array, one item per line of output. All lines will be of equal size.

toRasterFormat()

Mike42\Escpos\EscposImage::toRasterFormat

(

)

Output the image in raster (row) format.

This can result in padding on the right of the image, if its width is not divisible by 8.

Exceptions

Exception

Where the generated data is unsuitable for the printer (indicates a bug or oversized image).

Returns

string The image in raster format.

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The documentation for this class was generated from the following file:

• src/Mike42/Escpos/EscposImage.php