On Wed, Apr 16, 2008 at 9:59 AM, tedd <[EMAIL PROTECTED]> wrote: > > At 9:41 AM -0400 4/16/08, Andrew Ballard wrote: > > > On Wed, Apr 16, 2008 at 7:56 AM, tedd <[EMAIL PROTECTED]> wrote: > > > > > At 6:48 PM +0900 4/16/08, Dave M G wrote: > > > > > > > PHP list, > > > > > > > > I have a PHP script that resizes an image. It takes just about > whatever > > > size and shrinks and crops it down to 320X240. > > > > > > > > I've found that these days, it's not uncommon for people to take > images > > > straight off their digital camera, which can be 3000X2000 pixels in > image > > > size, even if the jpeg file containing the image is only 200 KB. When > > > working with the image, it gets uncompressed and takes up a lot of > memory. > > > > > > > > > > You might want to look into using javascript to trim the file down to a > > > respectable size before uploading. > > > > > > Cheers, > > > > > > tedd > > > > > > > I'd be interested in seeing an example of how you actually plan on > > doing that, Tedd. JavaScript can't access the file from an input > > field, and I'm not aware of any JavaScript image handling functions > > either. > > > > Andrew > > > > > I saw one the other day that caught my eye -- will look into it. > > > > Cheers, > > tedd
The first problem I see implementing the approach is the JavaScript sandbox. JavaScript is allowed to read the text of the input file field (and thus know the file name and path once a file has been selected); it cannot access the disk to actually get to the image or do anything with it. From here, I'm thinking there are a couple things you could do with JavaScript. The first would be to embed the image into the web page using an IMG tag, which would allow you to determine the pixel dimensions (but not the actual file size). The second would be what Gmail seems to do, and actually upload the form to their server with some sort of AJAX request, at which time your server could return information on the size of the file. However, if the file is too large, you're back to the original problem of needing to increase the RAM limit in PHP. The second problem is, as I said, I'm not aware of any JavaScript that can manipulate the image. JavaScript can cause the display of an image to be resized within the browser, but that doesn't actually affect the stored file. I don't know, but I guess if you could actually get to the bits, you could probably write an algorithm in JavaScript to resize an image by manipulating the bits, but I think it would be dreadfully slow if it would even run without running out of resources. I think the only pure-client options are either Java (which would require special permissions to get out of its own sandbox) or ActiveX. If you know of some other approach, I'd be interested to see how it works. Andrew -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
