Re: Extracting a blob from DBI to a buffer

[haj]

Unfortunately, Image::Epeg-new(\$jpg_data); isn’t working.

What makes you write that? I'm too lazy to whip up a database, but the following code pulls a JPEG image into a scalar and thumbnails it successfully.

use 5.020;
use warnings;

use Image::Epeg qw(:constants);
use LWP::Simple;

# Copyright notice for the image:
# By Randal Schwartz from Portland, OR, USA - Flickr, CC BY-SA 2.0,
# https://commons.wikimedia.org/w/index.php?curid=2938351

my $image = get("https://upload.wikimedia.org/wikipedia/commons/b/b3/L
+arry_Wall_YAPC_2007.jpg");

die "Failed to load the image" unless defined $image;

my $epeg = Image::Epeg->new(\$image);
$epeg->resize(150,150,MAINTAIN_ASPECT_RATIO);
$epeg->write_file("thumbnail.jpg");

Side note: You need to have LWP::Protocol::https installed for this code.

[Serene Hacker]

Thanks everyone!

OK, Image::Epeg-new(\$jpg_data); does work. The $epg->resize function fails occasionally -- even though they're valid jpegs and larger than the crop size. (And the call is more likely to fail, the larger the crop size). And $epg->get_data occasionally fails (sticking exactly 64k zeroes at the beginning of the data, and then ever larger amounts of junk (?) on the end) -- even though resize returned 1.

There's not much point in posting code yet. I'm still trying to figure out if there's anything wrong with the input files. Or whether there's something wrong with my installation -- or even the hardware! Anyway -- whatever's going on, it has nothing to do with extracting a blob from DBI. :-)

I'm running perl 5.28.2 on Mac OS X 10.14.6 with MacPorts. I recently re-installed Xcode (and the command line tools, and MacPorts and Perl etc.) -- a software update to Xcode had changed some directories to from 10.14 to 10.15 (!) Some builds still fail (arm-none-eabi-gdb in MacPorts, and Image::Magick in CPAN) soooo, not sure what (if anything) is wrong...If I manage to narrow things down to a nice test I'll start a different thread.