NAME
Image::Imlib2 - Interface to the Imlib2 image library
SYNOPSIS
use Image::Imlib2;
# create a new image
my $image = Image::Imlib2->new(200, 200);
# or load an image
$image = Image::Imlib2->load("foo.png");
# Enable the alpha channel support
$image->has_alpha(1);
# set a colour (rgba, so this is transparent orange)
$image->set_color(255, 127, 0, 127);
# draw a rectangle
$image->draw_rectangle(50, 50, 50, 50);
# draw a filled rectangle
$image->fill_rectangle(150, 50, 50, 50);
# draw a line
$image->draw_line(0, 0, 200, 50);
# set quality before saving
$image->set_quality(50);
# save out
$image->save('out.png');
# create a polygon
my $poly = Image::Imlib2::Polygon->new();
# add some points
$poly->add_point(0, 0);
$poly->add_point(100, 0);
$poly->add_point(100, 100);
$poly->add_point(0, 100);
# fill the polygon
$poly->fill();
# draw it closed on image
$image->draw_polygon($poly, 1);
# create a color range
my $cr = Image::Imlib2::ColorRange->new();
# add a color
my ($distance, $red, $green, $blue, $alpha) = (15, 200, 100, 50, 20);
$cr->add_color($distance, $red, $green, $blue, $alpha);
# draw it
my($x, $y, $width, $height, $angle) = (20, 30, 200, 200, 1);
$image->fill_color_range_rectangle($cr, $x, $y,
$width, $height, $angle);
DESCRIPTION
Image::Imlib2 is a Perl port of Imlib2, a graphics library that does
image file loading and saving as well as manipulation, arbitrary polygon
support, etc. It does ALL of these operations FAST. It allows you to
create colour images using a large number of graphics primitives, and
output the images in a range of formats.
Image::Imlib2::Polygon and Image::Imlib2::ColorRange are described
following Image::Imlib2 but may be referenced before their description.
Note that this is an early version of my attempt at a Perl interface to
Imlib2. Currently, the API is just to test things out. Not everything is
supported, but a great deal of functionality already exists. If you
think the API can be tweaked to be a bit more intuitive, drop me a line!
Note that a development version of Imlib2 must be installed before
installing this module.
Exported constants
TEXT_TO_RIGHT
TEXT_TO_LEFT
TEXT_TO_UP
TEXT_TO_DOWN
TEXT_TO_ANGLE
To be used as the direction parameter for text functions that accept it.
METHODS (Image::Imlib2)
new
This will create a new, blank image. If the dimensions aren't specified,
it will default to 256 x 256.
my $image = Image::Imlib2->new(100, 100);
The contents of this image at creation time are undefined - they could
be garbage memory. You should clear the image if necessary.
new_transparent
This will create a new fully-transparent image. If the dimensions aren't
specified, it will default to 256 x 256.
my $image = Image::Imlib2->new_transparent(100, 100);
new_using_data
This will create a new image with the specified pixel data, which must
be a packed string. If the dimensions are not specified, it will default
to 256 x 256.
my $pixel = pack('CCCC', 255, 127, 0, 255); # ARGB
my $image = Image::Imlib2->new_using_data(100, 100, $pixel x (100*100));
load
This will load an existing graphics file and create a new image object.
It reads quite a few different image formats.
my $image = Image::Imlib2->load("foo.png");
save
This saves the current image out. Currently this is in PNG if the format
has not been set using image_set_format().
$image->save("out.png");
image_set_format (format)
This will set the image format for future save operations. format is a
string and may be "jpeg", "tiff", "png", etc. The exact number of
formats supported depends on how you built imlib2.
$image->image_set_format("jpeg"); # Convert image to JPG
set_quality
This sets the quality of the saved picture - lower the quality to get
smaller filesizes.
$image->set_quality(50);
set_color (r, g, b, a) or set_colour (r, g, b, a)
This sets the colour that the drawing primitives will use. You specify
the red, green, blue and alpha components, which should all range from 0
to 255. The alpha component specified how transparent the colour is: 0
is fully transparent (so drawing with it will be pointless), 127 is
half-transparent, and 255 is fully opaque. Many examples:
$image->set_colour(255, 255, 255, 255); # white
$image->set_colour( 0, 0, 0, 255); # black
$image->set_colour(127, 127, 127, 255); # 50% gray
$image->set_colour(255, 0, 0, 255); # red
$image->set_colour( 0, 255, 0, 255); # green
$image->set_colour( 0, 0, 255, 255); # blue
$image->set_colour(255, 127, 0, 127); # transparent orange
Warning: this sets a global variable for the draw color.
draw_point (x, y)
This colours a point in the image in the currently-selected colour. Note
that the coordinate system used has (0, 0) at the top left, with (50, 0)
to the right of the top left, (0, 50) below the top left, and (50, 50)
to the bottom right of the top left.
$image->draw_point(50, 50);
query_pixel (x, y)
This returns the colour of a pixel in the image. It returns the red,
green, blue and alpha components:
my($r, $g, $b, $a) = $image->query_pixel(50,50);
draw_line (x1, y1, x2, y2)
This draws a line between two points in the currently-selected colour.
The following draws between the (0, 0) and (100, 100) points:
$image->draw_line(0, 0, 100, 100);
draw_rectangle (x, y, w, h)
This draws a the outline of a rectangle with the top left point at (x,
y) and having width w and height h in the current colour.
$image->draw_rectangle(0, 0, 50, 50);
fill_rectangle (x, y, w, h)
This draws a filled rectangle with the top left point at (x, y) and
having width w and height h in the current colour.
$image->fill_rectangle(0, 0, 50, 50);
draw_ellipse (x, y, w, h)
This draws an ellipse which has center (x, y) and horizontal amplitude
of w and vertical amplitude of h in the current colour. Note that
setting w and h to the same value will draw a circle.
$image->draw_ellipse(100, 100, 50, 50);
fill_ellipse (x, y, w, h)
This draws a filled ellipse which has center (x, y) and horizontal
amplitude of w and vertical amplitude of h in the current colour. Note
that setting w and h to the same value will draw a filled circle.
$image->fill_ellipse(100, 100, 50, 50);
add_font_path (dir)
This function adds the directory path to the end of the current list of
directories to scan for truetype (TTF) fonts.
$image->add_font_path("./ttfonts");
load_font (font)
This function will load a truetype font from the first directory in the
font path that contains that font. The font name format is
"font_name/size". For example. If there is a font file called cinema.ttf
somewhere in the font path you might use "cinema/20" to load a 20 pixel
sized font of cinema.
Note that this font will be used from now on, much like set_colour does
for colours.
$image->load_font("cinema/20");
Warning: this sets a global variable for the current font.
get_text_size (text, direction, angle)
This function returns the width and height in pixels the text string
would use up if drawn with the current font. direction and angle are
optional and deault to TEXT_TO_RIGHT and 0, respectively.
my($w, $h) = $image->get_text_size("Imlib2 and Perl!");
my($w1, $w2) = $image->get_text_size("Crazy text",
TEXT_TO_UP, 1);
draw_text (x, y, text, direction, angle)
This draws the text using the current font and colour onto the image at
position (x, y). direction and angle are optional and deault to
TEXT_TO_RIGHT and 0, respectively.
$image->draw_text(50, 50, "Groovy, baby, yeah!");
$image->draw_text(50, 50, "Sweet, baby, yeah!",
TEXT_TO_UP, 1.571);
autocrop
This creates a duplicate of the image which is automatically cropped to
remove the background colour from the outside of the image:
my $cropped_image = $image->autocrop;
autocrop_dimensions
This returns the x, y, width and height rectangle in an image which
would hold the results of the autocrop method:
my($x, $y, $w, $h) = $image->autocrop_dimensions;
crop (x, y, w, h)
This creates a duplicate of a x, y, width, height rectangle in the
current image and returns another image.
my $cropped_image = $image->crop(0, 0, 50, 50);
blend (source_image, merge_alpha, sx, sy, sw, sh, dx, dy, dw, dh)
This will blend the source rectangle x, y, width, height from the
source_image onto the current image at the destination x, y location
scaled to the width and height specified. If merge_alpha is set to 1 it
will also modify the destination image alpha channel, otherwise the
destination alpha channel is left untouched.
$image->blend($cropped_image, 0, 0, 0, 50, 50, 200, 0, 50, 50);
blur (radius)
This will blur the image. A radius of 0 has no effect, 1 and above
determine the blur matrix radius that determine how much to blur the
image.
$image->blur(1);
sharpen (radius)
This sharpens the image. The radius affects how much to sharpen by.
$image->sharpen(1);
clone ()
This creates an exact duplicate of the current image.
$cloned = $image->clone;
draw_polygon (polygon, closed)
This will draw polygon (of type Imlib2::Image::Polygon) on the the
image. The the polygon is drawn closed is closed is 1 and open if closed
is 0.
$image->draw_polygon($poly, 1);
fill_color_range_rectangle(color_range, x, y, w, h, angle);
This uses the color range color_range to fille a rectangle with points
x, y, x+width, y+width.
$image->fill_color_range_rectangle($cr, 10, 20, 100, 150, 0);
image_orientate (steps)
This will rotate the image by steps*90 degrees, so to rotate by 90
degrees set to 1, for 180 degrees set to 2, etc.
$image->image_orientate(1); # Rotate by 90 degrees.
create_rotated_image(radians)
Create a new image, rotated from the original by a number of radians.
For example, to rotate 45 degrees:
my $rotated = $image->create_rotated_image(45 / 360 * 3.141519*2);
create_scaled_image (x, y)
Create a new image, scaled from the original to the dimensions given in
x and y. If x or y are 0, then retain the aspect ratio given in the
other.
$image2=$image->create_scaled_image(100,100); # Scale to 100x100 pixels
create_transparent_image (alpha)
Create a new image, based upon the original but with a fixed alpha
value. This will create a transparent image that you can then blend onto
other images. Alpha ranges from 0 to 255:
my $new = $image->create_transparent_image(64);
create_blended_image (percent)
Create a new image, which is percent% of source1 and (100-percent)% of
source2. This is used for fading bedtween two images. Percent ranges
from 0 to 100:
my $new = $source1->create_blended_image($source2, 50);
flip_horizontal ()
This will flip/mirror the image horizontally.
$image->flip_horizontal();
flip_vertical ()
This will flip/mirror the image vertically.
$image->flip_vertical();
flip_diagonal ()
This will flip/mirror the current image diagonally (good for quick and
dirty 90 degree rotations if used before to after a horizontal or
vertical flip).
$image->flip_diagonal();
has_alpha (BOOLEAN)
Queries and/or sets the alpha support flag for the image. Note that
alpha is on by default when you create an image:
if ($image->has_alpha) {
# do something requiring alpha support
}
# Enable the alpha channel
$image->has_alpha(1);
set_cache_size (INT)
By default, Imlib2 will not cache any images loaded from disk.
If you set a cache size then Imlib2 will cache all loaded images (up to
this size) and will use this cache to avoid loading images from disk.
Sets the size of the image cache. Reducing this value will cause the
cache to be emptied. You can turn off caching all together by setting
this to zero.
Even without a cache, as long as you have a reference to an image in
memory that image will be returned immediately without checking the
disk.
Image::Imlib2->set_cache_size(1024 * 1024);
my $image = Image::Imlib2->load("foo.jpg"); # image loaded from disk
... later, somewhere else, after $image has gone away ...
my $image = Image::Imlib2->load("foo.jpg"); # same image, even if changed on disk
... later, somewhere else, after $image has gone away ...
Image::Imlib2->set_cache_size(0);
my $image = Image::Imlib2->load("foo.jpg"); # image loaded from disk
my $image2 = Image::Imlib2->load("foo.jpg"); # same image as before, not reloaded
get_cache_size ()
Returns the maximum size of the Image cache.
set_changes_on_disk ()
Called on an Image::Imlib2 instance that you have loaded from disk, this
method tells imlib that it should take extra care when caching the image
for this filename. Next time the load method is called for this image's
file name Imlib will check the modification time for the file on disk
compared to the cached version and take appropriate action.
my $image = Image::Imlib2->load("foo.jpg");
$image->set_changes_on_disk();
...later...
# reloads image from disk if mod time has changed (otherwise use cached)
my $image = Image::Imlib2->load("foo.jpg");
Calling this method on a loaded image tells Imlib2 to look at the disk
and compare mtimes with it's loaded copy - by default, this is not the
case, so even if a file changes on disk, it won't be re-loaded.
will_blend (BOOL)
Changes the setting for whether drawing blends with existing pixels in
the image or overwrites those pixels. Defaults to true. Returns the new
value. If no argument is passed, just returns the current value.
Warning: this sets a global variable for blending.
find_colour
This returns the x and y coordinates for the first pixel of the current
colour it finds in the image. It returns undef if it doesn't find the
colour:
# find a red pixel
$i->set_colour(255, 0, 0, 255);
my($rx, $ry) = $i->find_red;
fill
This flood fills the image, starting at the x and y coordinates and
filling every pixel under it with the current colour:
$i->fill($x, $y);
METHODS (Image::Imlib2::Polygon)
new
This will create a new polygon for use with Image::Imlib2::draw_polygon.
my $poly = Image::Imlib2::Polygon->new();
add_point (x, y)
Adds a point to the polygonal construct.
$poly->add_point(10,10);
fill
Fills polygon in the current context.
$poly->fill();
METHODS (Image::Imlib2::ColorRange)
new
Creates a new color range.
my $cr = Image::Imlib2::ColorRange->new();
add_color (distance, red, green, blue, alpha)
Similar to set_colour, but adds the color to the color range at the
specified distance.
$cr->add_color(10, 255, 127, 0, 66);
Warning: this sets a global variable for the draw color.
width
Returns the current width of the image.
my $width = $image->width;
height
Returns the current height of the image.
my $height = $image->height;
DEPRECATED METHOS
get_width
Returns the current width of the image. Use width() instead.
my $width = $image->get_width;
get_height
Returns the current height of the image. Use height() instead.
my $height = $image->get_height;
AUTHOR
Leon Brocard, acme@astray.com
COPYRIGHT
Copyright (c) 2000-9 Leon Brocard. All rights reserved.
LICENSE
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.