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imagecopyresized

(PHP 3, PHP 4, PHP 5)

imagecopyresized -- Copy and resize part of an image

Descrizione

bool imagecopyresized ( resource dst_image, resource src_image, int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h )

imagecopyresized() copies a rectangular portion of one image to another image. dst_image is the destination image, src_image is the source image identifier. If the source and destination coordinates and width and heights differ, appropriate stretching or shrinking of the image fragment will be performed. The coordinates refer to the upper left corner. This function can be used to copy regions within the same image (if dst_image is the same as src_image) but if the regions overlap the results will be unpredictable.

Elenco dei parametri

dst_im

Destination image link resource

src_im

Source image link resource

dst_x

x-coordinate of destination point

dst_y

y-coordinate of destination point

src_x

x-coordinate of source point

src_y

y-coordinate of source point

dst_w

Destination width

dst_h

Destination height

src_w

Source width

src_h

Source height

Valori restituiti

Restituisce TRUE in caso di successo, FALSE in caso di fallimento.

Esempi

Esempio 1. Resizing an image

This example will display the image at half size.

<?php
// File and new size
$filename = 'test.jpg';
$percent = 0.5;

// Content type
header('Content-type: image/jpeg');

// Get new sizes
list($width, $height) = getimagesize($filename);
$newwidth = $width * $percent;
$newheight = $height * $percent;

// Load
$thumb = imagecreatetruecolor($newwidth, $newheight);
$source = imagecreatefromjpeg($filename);

// Resize
imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);

// Output
imagejpeg($thumb);
?>

The image will be output at half size, though better quality could be obtained using imagecopyresampled().

Note

Nota: There is a problem due to palette image limitations (255+1 colors). Resampling or filtering an image commonly needs more colors than 255, a kind of approximation is used to calculate the new resampled pixel and its color. With a palette image we try to allocate a new color, if that failed, we choose the closest (in theory) computed color. This is not always the closest visual color. That may produce a weird result, like blank (or visually blank) images. To skip this problem, please use a truecolor image as a destination image, such as one created by imagecreatetruecolor().

Vedere anche:

imagecopyresampled()



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