imageflip

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

imageflipFlips an image using a given mode

Description

imageflip(GdImage $image, int $mode): bool

Flips the image image using the given mode.

Parameters

image

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

mode

Flip mode, this can be one of the IMG_FLIP_* constants:

Constant Meaning
IMG_FLIP_HORIZONTAL Flips the image horizontally.
IMG_FLIP_VERTICAL Flips the image vertically.
IMG_FLIP_BOTH Flips the image both horizontally and vertically.

Return Values

Returns true on success or false on failure.

Changelog

Version Description
8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

Examples

Example #1 Flips an image vertically

This example uses the IMG_FLIP_VERTICAL constant.

<?php
// File
$filename = 'phplogo.png';

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

// Load
$im = imagecreatefrompng($filename);

// Flip it vertically
imageflip($im, IMG_FLIP_VERTICAL);

// Output
imagejpeg($im);
imagedestroy($im);
?>

The above example will output something similar to:

Output of example: Vertically flipped image

Example #2 Flips the image horizontally

This example uses the IMG_FLIP_HORIZONTAL constant.

<?php
// File
$filename = 'phplogo.png';

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

// Load
$im = imagecreatefrompng($filename);

// Flip it horizontally
imageflip($im, IMG_FLIP_HORIZONTAL);

// Output
imagejpeg($im);
imagedestroy($im);
?>

The above example will output something similar to:

Output of example: Horizontally flipped image

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User Contributed Notes 1 note

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5
Daniel Klein
8 years ago
If you're using PHP < 5.5 you can use this code to add the same functionality. If you pass the wrong $mode in it will silently fail. You might want to add your own error handling for this case.

<?php
if (!function_exists('imageflip')) {
define('IMG_FLIP_HORIZONTAL', 0);
define('IMG_FLIP_VERTICAL', 1);
define('IMG_FLIP_BOTH', 2);

function
imageflip($image, $mode) {
switch (
$mode) {
case
IMG_FLIP_HORIZONTAL: {
$max_x = imagesx($image) - 1;
$half_x = $max_x / 2;
$sy = imagesy($image);
$temp_image = imageistruecolor($image)? imagecreatetruecolor(1, $sy): imagecreate(1, $sy);
for (
$x = 0; $x < $half_x; ++$x) {
imagecopy($temp_image, $image, 0, 0, $x, 0, 1, $sy);
imagecopy($image, $image, $x, 0, $max_x - $x, 0, 1, $sy);
imagecopy($image, $temp_image, $max_x - $x, 0, 0, 0, 1, $sy);
}
break;
}
case
IMG_FLIP_VERTICAL: {
$sx = imagesx($image);
$max_y = imagesy($image) - 1;
$half_y = $max_y / 2;
$temp_image = imageistruecolor($image)? imagecreatetruecolor($sx, 1): imagecreate($sx, 1);
for (
$y = 0; $y < $half_y; ++$y) {
imagecopy($temp_image, $image, 0, 0, 0, $y, $sx, 1);
imagecopy($image, $image, 0, $y, 0, $max_y - $y, $sx, 1);
imagecopy($image, $temp_image, 0, $max_y - $y, 0, 0, $sx, 1);
}
break;
}
case
IMG_FLIP_BOTH: {
$sx = imagesx($image);
$sy = imagesy($image);
$temp_image = imagerotate($image, 180, 0);
imagecopy($image, $temp_image, 0, 0, 0, 0, $sx, $sy);
break;
}
default: {
return;
}
}
imagedestroy($temp_image);
}
}
?>
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