I have an image $file ( eg ../image.jpg )
which has a mime type $type
How can I output it to the browser?
If you have the liberty to configure your webserver yourself, tools like mod_xsendfile (for Apache) are considerably better than reading and printing the file in PHP. Your PHP code would look like this:
header("Content-type: $type");
header("X-Sendfile: $file"); # make sure $file is the full path, not relative
exit();
mod_xsendfile picks up the X-Sendfile header and sends the file to the browser itself. This can make a real difference in performance, especially for big files. Most of the proposed solutions read the whole file into memory and then print it out. That's OK for a 20kbyte image file, but if you have a 200 MByte TIFF file, you're bound to get problems.