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imager::security(3pm) [debian man page]

Imager::Security(3pm)					User Contributed Perl Documentation				     Imager::Security(3pm)

NAME
Imager::Security - brief notes on security and image processing SYNOPSIS
# keep abreast of security updates apt-get update && apt-get upgrade yum upgrade pkgin update && pkgin upgrade # or local equivalent # limit memory use use Imager; # only images that use up to 10MB Imager->set_file_limits(bytes => 10_000_000); DESCRIPTION
There's two basic security considerations when dealing with images from an unknown source: o keeping your libraries up to date o limiting the amount of memory used to store images Keeping libraries up to date Image file format libraries such as "libpng" or "libtiff" have relatively frequent security updates, keeping your libraries up to date is basic security. If you're using user supplied fonts, you will need to keep your font libraries up to date too. Limiting memory used With compression, and especially with pointer formats like TIFF, it's possible to store very large images in a relatively small file. If you're receiving image data from an untrusted source you should limit the amount of memory that Imager can allocate for a read in image file using the "set_file_limits()" method. Imager->set_file_limits(bytes => 10_000_000); You may also want to limit the maximum width and height of images read from files: Imager->set_file_limits(width => 10_000, height => 10_000, bytes => 10_000_000); This has no effect on images created without a file: # succeeds my $image = Imager->new(xsize => 10_001, ysize => 10_001); You can reset to the defaults with: Imager->set_file_limits(reset => 1); AUTHOR
Tony Cook <tonyc@cpan.org> perl v5.14.2 2012-06-04 Imager::Security(3pm)

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Imager::LargeSamples(3pm)				User Contributed Perl Documentation				 Imager::LargeSamples(3pm)

NAME
Imager::LargeSamples - track/document large sample support SYNOPSIS
# make a large sample image my $im = Imager->new(..., bits => 16); # call some method my $result = $im->$method(...); # was the image modified at its full sample size DESCRIPTION
Imager has had in-memory support for large samples for years now, but many methods still don't work at the higher sample size when supplied with a large sample image. This document will track which methods support large samples and which don't, for future improvements. Support by method Method Support Notes ------ ------- ----- arc Partial [1] box Partial [2] circle Partial [1] convert Full copy Full crop Full difference Full filter Partial Depends on the filter. flip Full flood_fill Partial [1] getpixel Full getsamples Full getscanline Full map None masked Full matrix_transform Full paste Full polygon Partial [1] polyline None read Partial See L<File format large sample support> read_multi Partial See L<File format large sample support> rotate Full rubthrough Full scale Partial Some qtypes support large samples scaleX None scaleY None setpixel Full setscanline Full string Full Preserves large samples, but most font drivers generate 8 or fewer bits of levels of coverage. transform None transform2 None write Partial See L<File format large sample support> write_multi Partial See L<File format large sample support> [1] filling an area using the fill parameter works at the full depth of the image, using filled => 1 and color works at 8-bits/sample [2] box() will fill the area at the supplied color, but outline at 8-bits/sample. File format large sample support Format Format samples Imager support ------ -------------- -------------- BMP 8 8 GIF 8 8 ICO 8 8 JPEG 8, 12 8 PBM 1 1 PGM/PPM 1-16 read any, writes 8, 16 PNG 1, 2, 4, 8, 16 8 RAW 8 SGI 8, 16 8, 16 TGA 8 8 TIFF (many) read/write 8, 16, 32 contig rgb/grey images read/write bi-level read/write 4/8 paletted images Filter larger sample support Filter Large sample support ------ -------------------- autolevels No bumpmap No bumpmap_complex No contrast No conv Yes fountain Yes gaussian Yes gradgen No hardinvert Yes mosaic No postlevels No radnoise No turbnoise No unsharpmask Yes watermark No AUTHOR
Tony Cook <tonyc@cpan.org> perl v5.14.2 2011-06-06 Imager::LargeSamples(3pm)
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