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PHP provides some powerful image processing function libraries, such as the GD library, which can help developers process images on the server side. In this article, we will explore how to achieve more powerful image processing effects by combining imageflip and imagecopy functions. We will use several examples to illustrate how to use these two functions for image flip and image copy operations.
The imageflip function is used to flip an image, which can flip the image horizontally or vertically. It accepts two parameters: the first parameter is the image resource and the second parameter is the flip type. Common flip types include:
IMG_FLIP_HORIZONTAL : Flip the image horizontally.
IMG_FLIP_VERTICAL : Flip the image vertically.
IMG_FLIP_BOTH : Flip horizontally and vertically at the same time.
The imagecopy function is used to copy an area of one image into another. Its common usage is to extract an area from one image and copy it to the location of another image.
The basic syntax of the imagecopy function is as follows:
bool imagecopy ( resource $dst_image , resource $src_image , int $dst_x , int $dst_y , int $src_x , int $src_y , int $src_w , int $src_h )
$dst_image : Target image resource.
$src_image : Source image resource.
$dst_x and $dst_y : The starting position where the copy area is placed in the target image.
$src_x and $src_y : The starting position of the copy area in the source image.
$src_w and $src_h : The width and height of the area to be copied.
Now, we will combine these two functions to perform some common image processing operations, such as: flipping and copying images, creating mirror effects, etc.
We first load an image, flip it horizontally, and then copy the flipped part to another image. Suppose we have an example.jpg image, the goal is to flip it horizontally and copy a portion of the area into the new image.
<?php
// Load the original image
$src_image = imagecreatefromjpeg('https://gitbox.net/images/example.jpg');
// Get the width and height of the image
$width = imagesx($src_image);
$height = imagesy($src_image);
// Create a blank image resource，Same size as source image
$dst_image = imagecreatetruecolor($width, $height);
// Flip the image horizontally
imageflip($src_image, IMG_FLIP_HORIZONTAL);
// Copy an area of the flipped image to the target image
imagecopy($dst_image, $src_image, 0, 0, 50, 50, $width - 50, $height - 50);
// Output new image to browser
header('Content-Type: image/jpeg');
imagejpeg($dst_image);
// Clean up resources
imagedestroy($src_image);
imagedestroy($dst_image);
?>
This code will:
Load the image example.jpg .
Flip the image horizontally.
Copy the flipped part into a new image and output it to the browser.
In this example, we flip the image vertically and then merge the flipped image with the original image to form a symmetric effect.
<?php
// Loading the image
$src_image = imagecreatefromjpeg('https://gitbox.net/images/example.jpg');
// Get the width and height of the image
$width = imagesx($src_image);
$height = imagesy($src_image);
// Create a new image，The width and height are twice as high as the original image
$dst_image = imagecreatetruecolor($width * 2, $height);
// Copy the original image to the left side of the target image
imagecopy($dst_image, $src_image, 0, 0, 0, 0, $width, $height);
// Vertical flip original image
imageflip($src_image, IMG_FLIP_VERTICAL);
// Copy the flipped image to the right side of the target image
imagecopy($dst_image, $src_image, $width, 0, 0, 0, $width, $height);
// Output the merged image
header('Content-Type: image/jpeg');
imagejpeg($dst_image);
// Clean up resources
imagedestroy($src_image);
imagedestroy($dst_image);
?>
This code will:
Load the image example.jpg .
Copy the original image to the left of the new image.
Flip the image vertically and copy the flipped image to the right.
Output the merged image.
Mirroring is a common image processing effect. The following code shows how to achieve this effect through imageflip and imagecopy functions.
<?php
// Loading the image
$src_image = imagecreatefromjpeg('https://gitbox.net/images/example.jpg');
// Get the width and height of the image
$width = imagesx($src_image);
$height = imagesy($src_image);
// Create a new image，Double the width of the original image
$dst_image = imagecreatetruecolor($width * 2, $height);
// Copy the original image to the left side of the target image
imagecopy($dst_image, $src_image, 0, 0, 0, 0, $width, $height);
// Flip the image horizontally
imageflip($src_image, IMG_FLIP_HORIZONTAL);
// Copy the flipped image to the right side of the target image
imagecopy($dst_image, $src_image, $width, 0, 0, 0, $width, $height);
// Output mirror effect image
header('Content-Type: image/jpeg');
imagejpeg($dst_image);
// Clean up resources
imagedestroy($src_image);
imagedestroy($dst_image);
?>
This code generates a mirror effect by flipping the image horizontally and merging the flipped image with the original image.
Combining imageflip and imagecopy functions, PHP can implement a variety of complex image processing techniques, such as image flip, copy and merging. These techniques can be widely used in scenes such as generating watermarks, making splicing maps, creating mirror effects, etc. By flexibly using these functions, developers can achieve more powerful image processing functions and improve the image processing capabilities of websites or applications.
Hopefully this article can help you better understand and use PHP's image processing functions. For more tips for PHP image processing, please refer to the official PHP documentation .
