imagecopyresampled

Copy and resize part of an image with resampling

true **imagecopyresampled** GdImage $dst_image GdImage $src_image int $dst_x int $dst_y int $src_x int $src_y int $dst_width int $dst_height int $src_width int $src_height

copies a rectangular

portion of one image to another image, smoothly interpolating pixel values so that, in particular, reducing the size of an image still retains a great deal of clarity. imagecopyresampled

In other words, will take a rectangular area from of width and height at position (,) and place it in a rectangular area of
of width and height at position (,). imagecopyresampled``src_image``src_width``src_height``src_x``src_y``dst_image``dst_width``dst_height``dst_x``dst_y

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 is the same as ) but if the regions overlap the results will be unpredictable. dst_image``src_image

dst_imagegd.image.destination

src_imagegd.image.source

dst_xx-coordinate of destination point.

dst_yy-coordinate of destination point.

src_xx-coordinate of source point.

src_yy-coordinate of source point.

dst_widthDestination width.

dst_heightDestination height.

src_widthgd.source.width

src_heightgd.source.height

return.true.always

Voorbeeld: Simple example

This example will resample an image to half its original size.

<?php
// The file
$filename = 'test.jpg';
$percent = 0.5;

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

// Get new dimensions
list($width, $height) = getimagesize($filename);
$new_width = $width * $percent;
$new_height = $height * $percent;

// Resample
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

// Output
imagejpeg($image_p, null, 100);
?>

Voorbeeld: Resampling an image proportionally

This example will display an image with the maximum width, or height, of 200 pixels.

<?php
// The file
$filename = 'test.jpg';

// Set a maximum height and width
$width = 200;
$height = 200;

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

// Get new dimensions
list($width_orig, $height_orig) = getimagesize($filename);

$ratio_orig = $width_orig/$height_orig;

if ($width/$height > $ratio_orig) {
   $width = $height*$ratio_orig;
} else {
   $height = $width/$ratio_orig;
}

// Resample
$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

// Output
imagejpeg($image_p, null, 100);
?>

Opmerking: > 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

imagecopyresized``imagescale``imagecrop

Vorige ← imagecopymergegray Volgende imagecopyresized →

imagecopyresampled

imagecopyresampled

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