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How to use imagecolorresolve() to create a retro style "low pixelation" image effect?
In modern web design, retro style has become a popular visual trend. Many designers and developers have begun to use "low pixelation" to simulate old computer graphics and create retro visual effects. In PHP, the imagecolorresolve() function can help us achieve this by generating pixelated images that look like low resolution.
imagecolorresolve() is a function in the PHP GD library that parses in an image and returns an RGB value of the specified color. It is often used in combination with other image processing functions to help us perform color analysis, modification and other operations of images.
To achieve a retro "low pixelation" effect, we need to use a technique that converts high-resolution images to low-resolution images. In short, it is to reduce the details of the picture so that the picture looks like it is composed of a few color blocks. By combining the imagecolorresolve() function, we can extract specific colors in the image and then simulate the effect of low-resolution images by recombining these color blocks.
First, we need to load the image. Suppose we already have an image file and we can use the imagecreatefromjpeg() or imagecreatefrommpng() functions to load the image.
<?php
$image = imagecreatefromjpeg('your-image.jpg'); // Loading pictures
if (!$image) {
die('Image loading failed');
}
?>
Next, we reduce the image size to a lower resolution, creating a pixelated effect. This can be implemented using the imagescale() function.
<?php
// Set new low resolution size
$new_width = imagesx($image) / 10;
$new_height = imagesy($image) / 10;
$image_resized = imagescale($image, $new_width, $new_height);
if (!$image_resized) {
die('Image scaling failed');
}
?>
When we reduce the image, we need to restore the image back to its original size. This can simulate low resolution pixelation effects.
<?php
$image_final = imagecreatetruecolor(imagesx($image), imagesy($image));
imagecopyresampled($image_final, $image_resized, 0, 0, 0, 0, imagesx($image), imagesy($image), $new_width, $new_height);
?>
Now we can use imagecolorresolve() to extract the main colors in the image. Suppose we want to keep only a few colors to enhance the retro style low-pixel effect.
<?php
// Get the color of a specific pixel point
$color = imagecolorat($image_final, 100, 100); // Get the location(100, 100)Pixel color
$rgb = imagecolorsforindex($image_final, $color); // Get the pixel'sRGBvalue
// use imagecolorresolve() Functions for color parsing
$resolved_color = imagecolorresolve($image_final, $rgb['red'], $rgb['green'], $rgb['blue']);
?>
Finally, save or output the modified image to the browser.
<?php
// Output image to browser
header('Content-Type: image/jpeg');
imagejpeg($image_final);
// Free up resources
imagedestroy($image);
imagedestroy($image_resized);
imagedestroy($image_final);
?>
Through the above steps, we successfully created a retro style low pixelation effect using the PHP and imagecolorresolve() functions. First create pixelated effects by reducing the image resolution, then extract the colors using imagecolorresolve() , and finally apply these colors to the image to obtain a retro-style visual effect.
In this way, you can easily add a touch of nostalgia to your web page or project, creating a unique low-pixelization style.
