export and save dialog box for images

Question

I am dynamically generating image in php. The image has a fixed name. I wants a button or hyperlink and onclick of that button, users should be able to export image rather than right click and save as image options. The problem is that in case of excel,pdf or doc files, I can specify the path of file and browser automatically asks for the open or save option but for images, it opens them in separate window.I want same dialog box for saving the image as for the other files like excel,pdf.Please help me on this.

Thanks

Answer 1

you can set the header to force download (for PHP):

header("Content-Description: File Transfer");
header("Content-Disposition: attachment; filename=$file");
header("Content-Type: image/png");

Then you can read the file

readfile($file);

Answer 2

What you can do is force image download using .htaccess if you are using Apache or directly via php using header tags

PHP Example

$file = "PATH TO FILE" ;
$fileName = basename($file);
$fileSize = filesize($file);
set_time_limit(0);
header("Pragma: public");
header("Expires: 0");  // Cache Options 
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");  // Cache Options 
header("Content-type: application/octet-stream");
header("Content-Disposition: filename=\" " . $fileName ."\"");
header("Content-length: $fileSize");
readfile($file);