How to save an image (using GD) to a file

belize has asked for the wisdom of the Perl Monks concerning the following question:

I am using the GD module to create an image and can get it to print directly to a web page using:

print "Content-type: image/gif\n\n";
print $im->gif;
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used as follows referencing an external CGI:

<IMG SRC="image.cgi">
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But if I use the image source as a sub-routine:

<IMG SRC="&image_routine">
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I get an ASCII printout on the page instead of the image.

So I would like to get the script to save the GD produced image as a file instead of outputting directly to the Webpage, but am having trouble getting it to work. I am using the following code:

$gif_data = $im->gif;
open (TEST,"$image_test") || die;
binmode TEST;
print TEST $gif_data;
close TEST
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The script runs fine, except the $image_test does not show.

Any ideas?

Comment on How to save an image (using GD) to a file Select or Download Code

Replies are listed 'Best First'.
Re: How to save an image (using GD) to a file by clemburg (Curate) on Nov 27, 2000 at 21:23 UTC
Why don't you use the CGI solution? With suitable parameters, you can have a very generic image generator with that. As for your problem, try this: `open (TEST,">$image_test") \|\| die;` [download] See? There is a ">" in front of the filename. And lastly, you will want to get a copy of Programming Web Graphics with Perl and Gnu Software. Update: tilly reminded me that the `die` in the code I gave is "uninformative". Well, he is right, of course. You should use: `open(TEST,">$image_test") \|\| die "Error: no open (write mode) for '$image_test': $!";` [download] Christian Lemburg Brainbench MVP for Perl http://www.brainbench.com	[reply] [d/l] [select]
Re: Re: How to save an image (using GD) to a file by belize (Deacon) on Nov 28, 2000 at 00:13 UTC
Thanks Christian. The ">" was the exact problem. The image now displays. I will modify the: `\|\| die` [download] to reflect an error message. Thanks again.	[reply] [d/l]
Re: How to save an image (using GD) to a file by KM (Priest) on Nov 27, 2000 at 21:24 UTC
open (TEST,"$image_test") \|\| die; You are opening for reading, not writing here. This may be your problem. I am assuming you have an older version of GD, since the newer ones don't support GIFs. Cheers, KM	[reply]
Re: How to save an image (using GD) to a file by arturo (Vicar) on Nov 27, 2000 at 21:03 UTC
I'd do what you're doin: open a file and print the image to that filehandle. Then, when I generated the HTML, have the `src` attribute point to the file I just created. UPDATE When you say "doesn't show" do you get the "image not found" image? . Have you checked to see that the image is where you think it is? Is the image file in a directory under the server's document tree? Does the image file have permissions such that the webserver process can read it?	[reply] [d/l]
Re: Re: How to save an image (using GD) to a file by belize (Deacon) on Nov 28, 2000 at 00:10 UTC
Thanks for your reply. That is exactly what I am trying to do, save it as an image. I found the answer from another response. I was leaving out the ">" when opening the file to write to. It now works. Now I am working on a next problem and will probably be asking for assistence once I research it a bit on my own. Thanks again for the rapid response.	[reply]


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