How to create 300ppi image in php?

Question

I need to know is there any method available in PHP through which I can create images in 300ppi? I saw the documentation of GD library but can't found any info. Is there any method through with I can process image and set the ppi?

Alternatively is there any method available in flash that convert the image resolution?

Thanks

Mani

Answer 1

Here a sample code you can use:

imagejpeg($image, $file, 75);

// Change DPI
$dpi_x   = 300;
$dpi_y   = 300;

$image   = file_get_contents($file);

// Update DPI information in the JPG header
$image[13] = chr(1);
$image[14] = chr(floor($dpi_x/255));
$image[15] = chr($dpi_x%255);
$image[16] = chr(floor($dpi_y/255));
$image[17] = chr($dpi_y%255);

// Write the new JPG
file_put_contents($file, $msg);