if ($input{fd}) { $fd=$input{fd} };
if ( $input{type} eq 'gif' ) {
- if (exists $input{data}) { $self->{IMG}=i_readgif_scalar($input{data}); }
- else { $self->{IMG}=i_readgif( $fd ) }
- if ( !defined($self->{IMG}) ) { $self->{ERRSTR}='unable to read gif image'; return undef; }
+ my $colors;
+ if ($input{colors} && !ref($input{colors})) {
+ # must be a reference to a scalar that accepts the colour map
+ $self->{ERRSTR} = "option 'colors' must be a scalar reference";
+ return undef;
+ }
+ if (exists $input{data}) {
+ if ($input{colors}) {
+ ($self->{IMG}, $colors) = i_readgif_scalar($input{data});
+ }
+ else {
+ $self->{IMG}=i_readgif_scalar($input{data});
+ }
+ }
+ else {
+ if ($input{colors}) {
+ ($self->{IMG}, $colors) = i_readgif( $fd );
+ }
+ else {
+ $self->{IMG} = i_readgif( $fd )
+ }
+ }
+ if ($colors) {
+ # we may or may not change i_readgif to return blessed objects...
+ ${$input{colors}} = [ map { NC(@$_) } @$colors ];
+ }
+ if ( !defined($self->{IMG}) ) {
+ $self->{ERRSTR}= 'reading GIF:'._error_as_msg(); return undef;
+ }
$self->{DEBUG} && print "loading a gif file\n";
} elsif ( $input{type} eq 'jpeg' ) {
if (exists $input{data}) { ($self->{IMG},$self->{IPTCRAW})=i_readjpeg_scalar($input{data}); }
$rc=i_writegifmc($self->{IMG},$fd,$input{gifplanes});
}
if ( !defined($rc) ) {
- $self->{ERRSTR}='unable to write gif image'; return undef;
+ $self->{ERRSTR} = "Writing GIF file: "._error_as_msg(); return undef;
}
$self->{DEBUG} && print "writing a gif file\n";
}
+sub flip {
+ my $self = shift;
+ my %opts = @_;
+ my %xlate = (h=>0, v=>1, hv=>2, vh=>2);
+ my $dir;
+ return () unless defined $opts{'dir'} and defined $xlate{$opts{'dir'}};
+ $dir = $xlate{$opts{'dir'}};
+ return $self if i_flipxy($self->{IMG}, $dir);
+ return ();
+}
+
+
# These two are supported for legacy code only
usefull if your data originates from somewhere else than a filesystem
such as a database over a DBI connection.
+If you are reading from a gif image file, you can supply a 'colors'
+parameter which must be a reference to a scalar. The referenced
+scalar will receive an array reference which contains the colors, each
+represented as an Imager::Color object.
+
+If you already have an open file handle, for example a socket or a
+pipe, you can specify the 'fd' parameter instead of supplying a
+filename. Please be aware that you need to use fileno() to retrieve
+the file descriptor for the file:
+
+ $img->read(fd=>fileno(FILE), type=>'gif') or die $img->errstr;
+
+For writing using the 'fd' option you will probably want to set $| for
+that descriptor, since the writes to the file descriptor bypass Perl's
+(or the C libraries) buffering. Setting $| should avoid out of order
+output.
+
*Note that load() is now an alias for read but will be removed later*
C<$img-E<gt>write> has the same interface as C<read()>. The earlier
use Imager;
print "@{[keys %Imager::formats]}";
+When reading raw images you need to supply the width and height of the
+image in the xsize and ysize options:
+
+ $img->read(file=>'foo.raw', xsize=>100, ysize=>100)
+ or die "Cannot read raw image\n";
+
+If your input file has more channels than you want, or (as is common),
+junk in the fourth channel, you can use the datachannels and
+storechannels options to control the number of channels in your input
+file and the resulting channels in your image. For example, if your
+input image uses 32-bits per pixel with red, green, blue and junk
+values for each pixel you could do:
+
+ $img->read(file=>'foo.raw', xsize=>100, ysize=>100, datachannels=>4,
+ storechannels=>3)
+ or die "Cannot read raw image\n";
+
+Normally the raw image is expected to have the value for channel 1
+immediately following channel 0 and channel 2 immediately following
+channel 1 for each pixel. If your input image has all the channel 0
+values for the first line of the image, followed by all the channel 1
+values for the first line and so on, you can use the interleave option:
+
+ $img->read(file=>'foo.raw', xsize=100, ysize=>100, interleave=>1)
+ or die "Cannot read raw image\n";
+
=head2 Multi-image files
Currently just for gif files, you can create files that contain more
=item gif_tran_color
A reference to an Imager::Color object, which is the colour to use for
-the palette entry used to represent transparency in the palette.
+the palette entry used to represent transparency in the palette. You
+need to set the transp option (see L<Quantization options>) for this
+value to be used.
=item gif_positions
=back
+This will only be used if the image has an alpha channel, and if there
+is space in the palette for a transparency colour.
+
=item tr_threshold
The highest alpha value at which a pixel will be made transparent when
transp is 'errdiff'. This can be any defined error diffusion type
except for custom (see errdiff below).
-=item tr_ordered
+=item tr_orddith
The type of ordered dither to perform on the alpha channel when transp
-is 'orddith'. Possible values are:
+is 'ordered'. Possible values are:
=over 4
=item random
-A semi-random map is used. The map is the same each time. Currently
-the default (which may change.)
+A semi-random map is used. The map is the same each time.
=item dot8
diagonal line dither
+=item tiny
+
+dot matrix dither (currently the default). This is probably the best
+for displays (like web pages).
+
=item custom
A custom dither matrix is used - see tr_map
=head2 Drawing Methods
IMPLEMENTATION MORE OR LESS DONE CHECK THE TESTS
-
DOCUMENTATION OF THIS SECTION OUT OF SYNC
It is possible to draw with graphics primitives onto images. Such
That copies the entire C<$logo> image onto the C<$dest> image so that the
upper left corner of the C<$logo> image is at (40,20).
+
+=head2 Flipping images
+
+An inplace horizontal or vertical flip is possible by calling the
+C<flip()> method. If the original is to be preserved it's possible to
+make a copy first. The only parameter it takes is the C<dir>
+parameter which can take the values C<h>, C<v>, C<vh> and C<hv>.
+
+ $img->flip(dir=>"h"); # horizontal flip
+ $img->flip(dir=>"vh"); # vertical and horizontal flip
+ $nimg = $img->copy->flip(dir=>"v"); # make a copy and flip it vertically
+
=head2 Blending Images
-
-To put an image or a part of an image directly into another it is
-best to call the C<paste()> method on the image you want to add to.
+
+To put an image or a part of an image directly
+into another it is best to call the C<paste()> method on the image you
+want to add to.
$img->paste(img=>$srcimage,left=>30,top=>50);
projects / imager.git / blobdiff