[PHP] Image Headers break when image is out of bounds
I've got a bit of a weird one here. I'm using PHP to output an image. This works fine when I output as a file, but when I try to feed it directly to the browser it fills the screen with random characters. I know I've got the headers right, as it works some of the time. The only thing I can spot when it does fail is that some of the image drawing commands are essentially drawing off the edge of the image area. I've checked the error logs, and the only errors/notices I can find today are a bug in phpMyAdmin and a missing favicon file, nothing to do with this script. Has anybody ever noticed a similar problem? Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Image Headers break when image is out of bounds
On Tue, 2009-08-11 at 19:02 +0100, Ashley Sheridan wrote: I've got a bit of a weird one here. I'm using PHP to output an image. This works fine when I output as a file, but when I try to feed it directly to the browser it fills the screen with random characters. I know I've got the headers right, as it works some of the time. The only thing I can spot when it does fail is that some of the image drawing commands are essentially drawing off the edge of the image area. I've checked the error logs, and the only errors/notices I can find today are a bug in phpMyAdmin and a missing favicon file, nothing to do with this script. Has anybody ever noticed a similar problem? Thanks, Ash http://www.ashleysheridan.co.uk Oh. I should note that there has been no headers sent already, as I put the image output part inside of a if(!headers_sent()) block. The headers I'm using for the PNG image are: header(Content-Type: image/png); header(Pragma: no-cache); header(Expires: 0); Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Image Headers break when image is out of bounds
On Tue, Aug 11, 2009 at 1:08 PM, Ashley Sheridan a...@ashleysheridan.co.ukwrote: On Tue, 2009-08-11 at 19:02 +0100, Ashley Sheridan wrote: I've got a bit of a weird one here. I'm using PHP to output an image. This works fine when I output as a file, but when I try to feed it directly to the browser it fills the screen with random characters. I know I've got the headers right, as it works some of the time. The only thing I can spot when it does fail is that some of the image drawing commands are essentially drawing off the edge of the image area. I've checked the error logs, and the only errors/notices I can find today are a bug in phpMyAdmin and a missing favicon file, nothing to do with this script. Has anybody ever noticed a similar problem? Thanks, Ash http://www.ashleysheridan.co.uk Oh. I should note that there has been no headers sent already, as I put the image output part inside of a if(!headers_sent()) block. The headers I'm using for the PNG image are: header(Content-Type: image/png); header(Pragma: no-cache); header(Expires: 0); Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php Take the if (!headers_sent()) out and always send the headers. -- - Adam Shannon ( http://ashannon.us )
Re: [PHP] Image Headers break when image is out of bounds
On Tue, 2009-08-11 at 13:29 -0500, Adam Shannon wrote: On Tue, Aug 11, 2009 at 1:08 PM, Ashley Sheridan a...@ashleysheridan.co.ukwrote: On Tue, 2009-08-11 at 19:02 +0100, Ashley Sheridan wrote: I've got a bit of a weird one here. I'm using PHP to output an image. This works fine when I output as a file, but when I try to feed it directly to the browser it fills the screen with random characters. I know I've got the headers right, as it works some of the time. The only thing I can spot when it does fail is that some of the image drawing commands are essentially drawing off the edge of the image area. I've checked the error logs, and the only errors/notices I can find today are a bug in phpMyAdmin and a missing favicon file, nothing to do with this script. Has anybody ever noticed a similar problem? Thanks, Ash http://www.ashleysheridan.co.uk Oh. I should note that there has been no headers sent already, as I put the image output part inside of a if(!headers_sent()) block. The headers I'm using for the PNG image are: header(Content-Type: image/png); header(Pragma: no-cache); header(Expires: 0); Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php Take the if (!headers_sent()) out and always send the headers. @Adam The headers_sent() wasa test to ensure that no other data was creeping into the headers before I wanted it to. Keeping it in does no harm, as it is basically saying, if there are no headers that have been sent, send the correct ones for the image. @Martin The image is being produced by PHP. The command I'm using to output the image is image_png(), and my OS is correctly reporting a PNG image (Linux will use the extension as a hint, but gets the filetype from the contents). Also, for further clarification, the junk output I'm getting has the letters PNG in the first few characters, so I'm pretty sure this is a PNG image yes! Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Image Headers break when image is out of bounds
@Adam The headers_sent() wasa test to ensure that no other data was creeping into the headers before I wanted it to. Keeping it in does no harm, as it is basically saying, if there are no headers that have been sent, send the correct ones for the image. But if there are headers that have been sent, it sounds like they would not have been the correct ones. Which I think would cause exactly the problem you're describing. Ben
Re: [PHP] Image Headers break when image is out of bounds
On Tue, Aug 11, 2009 at 11:52 AM, Ben Dunlap bdun...@agentintellect.comwrote: @Adam The headers_sent() wasa test to ensure that no other data was creeping into the headers before I wanted it to. Keeping it in does no harm, as it is basically saying, if there are no headers that have been sent, send the correct ones for the image. But if there are headers that have been sent, it sounds like they would not have been the correct ones. Which I think would cause exactly the problem you're describing. Ben Oops, looked back at your earlier post and it sounds like you only send the image inside the if(!headers_sent()) block. Never mind, pls disregard my earlier noise. Ben
Re: [PHP] Image Headers break when image is out of bounds
On Tue, 2009-08-11 at 11:54 -0700, Ben Dunlap wrote: On Tue, Aug 11, 2009 at 11:52 AM, Ben Dunlap bdun...@agentintellect.com wrote: @Adam The headers_sent() wasa test to ensure that no other data was creeping into the headers before I wanted it to. Keeping it in does no harm, as it is basically saying, if there are no headers that have been sent, send the correct ones for the image. But if there are headers that have been sent, it sounds like they would not have been the correct ones. Which I think would cause exactly the problem you're describing. Ben Oops, looked back at your earlier post and it sounds like you only send the image inside the if(!headers_sent()) block. Never mind, pls disregard my earlier noise. Ben Well, this will teach me to pay more attention. Turns out, I was attempting to output the image before the headers! It was a red herring that the image was displaying correctly when the drawing commands were all inside of the image area. It's probably more of a feature of Fx to try and recognise the content it's been sent if it can? Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
