(PHP 4 >= 4.0.7, PHP 5, PHP 7, PHP 8)
imagegd2 — Genera una imagen en formato GD2, hacia el navegador o un fichero
$image,$file = null,$chunk_size = 128,$mode = IMG_GD2_RAW
Genera o guarda el fichero file en formato GD2.
imageUn objeto GdImage, retornado por una de las funciones de creación de imágenes, como imagecreatetruecolor().
fileThe path or an open stream resource (which is automatically closed after this function returns) to save the file to. If not set or null, the raw image stream will be output directly.
chunk_sizeTamaño del fragmento.
mode
Puede ser IMG_GD2_RAW o
IMG_GD2_COMPRESSED. Por omisión, vale
IMG_GD2_RAW.
Esta función retorna true en caso de éxito o false si ocurre un error.
However, if libgd fails to output the image, this function returns true.
| Versión | Descripción |
|---|---|
| 8.0.3 |
file ahora es nulo.
|
| 8.0.0 |
image expects a GdImage
instance now; previously, a valid gd resource was expected.
|
Ejemplo #1 Mostrar una imagen GD2
<?php
// Creación de una imagen vacía y adición de texto
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5, "Un texto simple", $text_color);
// Mostrar la imagen
imagegd2($im);
?>
Ejemplo #2 Guardar una imagen GD2
<?php
// Creación de una imagen vacía y adición de texto
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5, "Un texto simple", $text_color);
// Guardar la imagen GD2
// El formato de fichero para imágenes GD2 es .gd2, ver http://www.libgd.org/GdFileFormats
imagegd2($im, 'simple.gd2');
?>Nota:
El formato GD2 se utiliza comúnmente para cargar rápidamente las partes de una imagen. Tenga en cuenta que el formato GD2 solo es utilizable en aplicaciones compatibles con GD2.
The GD and GD2 image formats are proprietary image formats of libgd. They have to be regarded obsolete, and should only be used for development and testing purposes.
You can use this function in combination with imagecreatefromstring() to clone the gd resource with minimum fuss (no writing to tmp file):
<?php
function cloneGd($gd)
{
ob_start();
imagegd2($gd);
return imagecreatefromstring(ob_get_clean());
}
?>This function produces an empty file (0 bytes) if a gdlib version is used without gd2 image format support. Which is planed to be removed completely with gdlib 3.yes, the gd2 file format does improve the speed of image creations as the data-setup is designed to be native for the GD function - ie, the image doesn't have to be converted to a usable format prior to processing.
you may also note that the newer gd2 format creates much smaller size files than the older imagegd function, certainly for images involving chunks of single colours anyway. you'll probably find this function most useful for saving overlay images or background images used in larger image creation scripts.
to read a ping or jpeg image (.png / .jpg) and save a .gd2 version to server...
$img = $_GET['img'];
if(file_exists($img))
{
$dim = getimagesize($img);
$cr = ($dim[2] < 4) ? ($dim[2] < 3) ? ($dim[2] < 2) ? NULL : imagecreatefromjpeg($img) : imagecreatefrompng($img) : Null;
if($cr !== NULL)
{
imagegd2($cr,substr($img,0,strrpos($img,'.')).'.gd2');
}
}
should save a copy with the same filename and directory using extension .gd2 - which can then be nicely and swiftly read using either imagecreatefromgd2 or imagecreatefromgd2part