Copy and resize part of an image

Описание

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.

Список параметров

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

Возвращаемые значения

Возвращает TRUE в случае успешного завершения или FALSE в случае возникновения ошибки.

Примеры

Example#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);
?>

Результатом выполнения данного примера будет что-то подобное:

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

Примечания

Note: 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().

Смотрите также

imagecopyresampled()