Pixie::Image
Inherits Pixie::Helpers / Reference / Object
Constructors
Creates a new blank image using the given width, height, and background color. The default background color is transparent, and the format is set to PNG.
Example:
image = Image.new(640, 480, Pixel::RED)Creates a new Image from the given LibMagick::MagickWand instance.
Creates a new Image from the given LibMagick::Image instance.
Creates a new Image from the given stream. See Image#read for
more information.
Creates a new Image from the given Array, where each element is
a layer in the image.
Creates a new Image with no data. This is the underlying method
used by all other constructors.
Class methods
Instance methods
Get the individual image (layer) at the given index.
Example:
image = Image.new("/path/to/image.gif")
image[0] # => ImageGet image details using special formatting characters. See https://imagemagick.org/script/escape.php
Example:
image = Image.new("/path/to/image.png")
image["%w"] # => "640"
image["%h"] # => "480"
image["%f"] # => "image.png"Apply an adaptive resize to the image.
Apply an adaptive threshold to the image.
Add noise to the image. Valid noise types are:
:undefined:uniform:gaussian:multiplicative_gaussian:impulse:laplacian:poisson:random
Automatically threshold the image using the given method. Valid methods are:
:undefined:kapur:ohtsu:triangle
Add a border to the image using the given Pixie::Pixel.
Apply a brightness and contrast adjustment to the image.
Detect edges in the image using the given radius.
Apply a charcoal effect to the image using the given radius and sigma.
Removes a region of a canvas and collapses the canvas to occupy the removed portion.
a variant of adaptive histogram equalization in which the contrast amplification is limited, so as to reduce this problem standard non-contrast limited AHE.
Clips along the named paths from the 8BIM profile, if present. Later operations take effect inside the path. Id may be a number if preceded with #, to work on a numbered path, e.g., "#1" to use the first path.
Replaces colors in the image from a color lookup table.
Composites a set of images while respecting any page offsets and disposal methods. GIF, MIFF, and MNG animation sequences typically start with an image background and each subsequent image varies in size and offset. Returns a new sequence where each image in the sequence is the same size as the first and composited with the next image in the sequence.
accepts a lightweight Color Correction Collection (CCC) file which solely contains one or more color corrections and applies the color correction to the image. Here is a sample CCC file:
<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2">
<ColorCorrection id="cc03345">
<SOPNode>
<Slope> 0.9 1.2 0.5 </Slope>
<Offset> 0.4 -0.5 0.6 </Offset>
<Power> 1.0 0.8 1.5 </Power>
</SOPNode>
<SATNode>
<Saturation> 0.85 </Saturation>
</SATNode>
</ColorCorrection>
</ColorCorrectionCollection>which includes the offset, slope, and power for each of the RGB channels as well as the saturation.
Apply color transformation to an image. The method permits saturation changes, hue rotation, luminance to alpha, and various other effects. Although variable-sized transformation matrices can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 for CMYKA (or RGBA with offsets). The matrix is similar to those used by Adobe Flash except offsets are in column 6 rather than 5 (in support of CMYKA images) and offsets are normalized (divide Flash offset by 255).
Blends the fill color with each pixel in the image.
Combines one or more images into a single image. The grayscale value of the pixels of each image in the sequence is assigned in order to the specified channels of the combined image. The typical ordering would be image 1 => Red, 2 => Green, 3 => Blue, etc.
Compares an image to a reconstructed image and returns the specified difference image.
Compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers.
Performs complex mathematics on an image sequence using the given oprtator. Valid operators are:
:undefined:add:conjugate:divide:magnitude_phase:multiply:real_imaginary:subtract
Composites two images together using the given operator.
See Image#complex for a list of valid operators.
Composites two images together using the given operator and gravity.
See Image#complex for a list of valid operators. Valid
gravities are:
:undefined:forget:north_west:north:north_east:west:center:east:south_west:south:south_east:static
Composite the images in the source wand over the images in the destination wand in sequence, starting with the current image in both lists. Each layer from the two image lists are composted together until the end of one of the image lists is reached. The offset of each composition is also adjusted to match the virtual canvas offsets of each layer. As such the given offset is relative to the virtual canvas, and not the actual image. Composition uses given x and y offsets, as the 'origin' location of the source images virtual canvas (not the real image) allowing you to compose a list of 'layer images' into the destination images. This makes it well suitable for directly composing 'Clears Frame Animations' or 'Coalesced Animations' onto a static or other 'Coalesced Animation' destination image list. GIF disposal handling is not looked at.
Special case:- If one of the image sequences is the last image (just a single image remaining), that image is repeatedly composed with all the images in the other image list. Either the source or destination lists may be the single image, for this situation. In the case of a single destination image (or last image given), that image will be cloned to match the number of images remaining in the source image list. This is equivalent to the "-layer Composite" Shell API operator.
For a list of valid operators, see Image#complex.
Returns the connected-components of the image uniquely labeled. The returned connected components image colors member defines the number of unique objects. Choose from 4 or 8-way connectivity.
Adds an image to the wand comprised of the pixel data you supply. The pixel data must be in scanline order top-to-bottom. The data can be char, short int, int, float, or double. Float and double require the pixels to be normalized [0..1], otherwise [0..Max], where Max is the maximum value the type can accomodate (e.g. 255 for char).
For example, to create a 640x480 image from unsigned red-green-blue character data:
image = Image.new
data = Array(UInt8).new(640 * 480 * 3) { 0u8 }
image.constitute(640, 480, "RGB", :char, data)Enhances the intensity differences between the lighter and darker elements of the image. Set sharpen to a value other than 0 to increase the image contrast otherwise the contrast is reduced.
Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available. You can also reduce the influence of a particular channel with a gamma value of 0.
Displaces an image's colormap by a given number of positions. If you cycle the colormap a number of times you can produce a psychodelic effect.
Compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers.
Delete a specific property of the image.
Example:
image = Image.new("/path/to/image.png")
image.delete_property("exif:GPSLatitude")Removes skew from the image. Skew is an artifact that occurs in scanned images because of the camera being misaligned, imperfections in the scanning or surface, or simply because the paper was not placed completely flat when scanned.
Reduces the speckle noise in an image while perserving the edges of the original image.
Distorts an image using various distortion methods, by mapping color lookups of the
source image to a new destination image usally of the same size as the source
image, unless best_fit is set to true.
Valid distortion methods are:
:undefined:affine:affine_projection:scale_rotate_translate:perspective:perspective_projection:bilinear_forward:bilinear_reverse:polynomial:arc:polar:de_polar:cylinder2plane:plane2cylinder:barrel:barrel_inverse:shepards:resize:sentinel
Example:
image = Image.new("/path/to/image.png")
image.distort(:affine, [0.0, 0.0, 0.0, 0.0, 0.0, 0.0])Enhances edges within the image with a convolution filter of the given radius. Using a radius of 0 will select a suitable radius for you.
Enhance edges within the image with a convolution filter of the given radius and sigma. Using a radius of 0 will select a suitable radius for you.
Extend the image as defined by the geometry, gravity, and wand background color. Set the (x,y) offset of the geometry to move the original wand relative to the extended wand.
Returns the chromaticity green primary point for the image as an x, y, z tuple.
Returns true if there are multiple images in the image set, and
pos is less than the number of images.
Returns true if there are multiple images in the image set, and
pos is greater than zero.
Generates an UInt64 hash value for this object.
This method must have the property that a == b implies a.hash == b.hash.
The hash value is used along with == by the Hash class to determine if two objects
reference the same hash key.
Subclasses must not override this method. Instead, they must define hash(hasher),
though usually the macro def_hash can be used to generate this method.
Returns an Array(Image), where each image is a layer in the image. Useful for
gif, pdf, psd, and any other image format with layers.
Example:
image = Image.new("/path/to/image.gif")
image.layers # => Array(Image)Create a montage from the images in the current set.
Extract pixel data from the image and return it as a multi-dimensional array of rows and columns, each containing an array of pixel data represnting the given map (defaulting to RGB). The map can be any combination or order of:
- R = red
- G = green
- B = blue
- A = alpha (0 is transparent)
- O = opacity (0 is opaque)
- C = cyan
- Y = yellow
- M = magenta
- K = black
- I = intensity (for grayscale)
- P = pad
Example:
image = Image.new("/path/to/image.png")
image.pixels.each do |row|
row.each do |col|
puts col # => [255, 255, 255]
end
endReturns the current position in the image set. Will always be zero for non-animated images.
Get a specific property of the image.
Example:
image = Image.new("/path/to/image.png")
image.property("date:create") # => "2019:01:01 12:00:00"Resize the image to fit within the specified dimensions. Stretching may occur.
Resize the image to not be larger than the specified dimensions. No stretching will occur.
Set the image's alpha channel to the given LibMagick::AlphaChannelOption.
Valid options are:
:undefined:activate:associate:background:copy:deactivate:discrete:disassociate:extract:off:on:opaque:remove:set:shape:transparent
Set the background color of the image to the given Pixie::Pixel.
Set the chromaticity blue primary point for the image to the given x, y, and z values.
Set the border color of the image to the given Pixie::Pixel.
Example:
image = Image.new("/path/to/image.png")
image.border_color = Pixel::REDSet the chromaticity green primary point for the image to the given x, y, and z values.
Sets the current position in the image set. Will always be zero for non-animated images.
Set a specific property of the image.
Example:
image = Image.new("/path/to/image.png")
image.set_property("exif:GPSLatitude", "40/1, 43/1, 54/1")Set the chromaticity red primary point for the image to the given x, y, and z values.