php gd dpi

In PHP, the GD (Graphics Draw) library does not have a specific function or method to directly retrieve the DPI (dots per inch) of an image. However, you can calculate the DPI by using the image's width and height in pixels and its physical dimensions in inches.

Here's an example of how you can calculate the DPI of an image using PHP GD:

<?php
// Path to the image file
$imagePath = 'path/to/image.jpg';

// Load the image using GD
$image = imagecreatefromjpeg($imagePath);

// Get the image size in pixels
$widthPx = imagesx($image);
$heightPx = imagesy($image);

// Get the physical dimensions of the image (in inches)
$inchWidth = (float) $widthPx / (float) $dpi;
$inchHeight = (float) $heightPx / (float) $dpi;

// Calculate the DPI
$dpi = max($widthPx / $inchWidth, $heightPx / $inchHeight);

// Output the DPI
echo "Image DPI: " . round($dpi, 2);

// Free up memory
imagedestroy($image);
?>

Note that the above code assumes that you have the DPI value available. If you don't have the DPI value, you can estimate it based on the physical size of the image in inches and the pixel dimensions.