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

Hi folks, I'm having trouble with Image::Magick.

For some time it's been quite happily resizing gifs for me, now I want it to do the same with jpegs. Something's going wrong in the conversion to or from a blob - I've narrowed it down to the following: 


#the original blob is in $blobdata - if I print it out here
# then I can see it's fine (exists, looks right).

#in the following line I've tried jpeg,jpg,JPG
my $image=Image::Magick->new(magick=>'JPEG');
$image->BlobToImage($blobdata);

my $newblob = $image -> ImageToBlob() ;
print $newblob; 
#at this point, $newblob appears to be empty

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Any ideas gratefully appreciated.

Cheers,
andy.

Replies are listed 'Best First'.
Re: Image::Magick BlobToImage() for jpegs
by andye (Curate) on May 04, 2001 at 15:45 UTC
    A bit more info: if I do 
    my $image=Image::Magick->new(magick=>'jpg');
$image->BlobToImage($blobdata);

use Data::Dumper; print Dumper($image);

    [download]
    then I get 
    $VAR1 = bless( [], 'Image::Magick' );

    [download]
    so I guess it's BlobToImage() which is failing.

    andy.

[reply]
[d/l]
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Re: Image::Magick BlobToImage() for jpegs
by Sinister (Friar) on May 04, 2001 at 15:10 UTC
    would it not be easier just to use the Resize function?

    Sinister greetings.
[reply]
      I plan to. But I have to convert it from a blob first. I've trimmed my code to find the broken part - and it appears to be the blob/image/blob conversion.

      andy.

[reply]
        Why do you need to specify the type of the image when defining it?

        Sinister greetings.
[reply]

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