class Magick::Image

Ruby-level Magick::Image methods

Public Instance Methods

annotate(draw, width, height, x, y, text, &block) click to toggle source

Provide an alternate version of Draw#annotate, for folks who want to find it in this class.

# File lib/RMagick.rb, line 786
def annotate(draw, width, height, x, y, text, &block)
  check_destroyed
  draw.annotate(self, width, height, x, y, text, &block)
  self
end
color_fill_to_border(x, y, fill) click to toggle source

Set all pixels that are neighbors of x,y and are not the border color to the fill color

# File lib/RMagick.rb, line 808
def color_fill_to_border(x, y, fill)
    color_flood_fill(border_color, fill, x, y, Magick::FillToBorderMethod)
end
color_floodfill(x, y, fill) click to toggle source

Set all pixels that have the same color as the pixel at x,y and are neighbors to the fill color

# File lib/RMagick.rb, line 801
def color_floodfill(x, y, fill)
    target = pixel_color(x, y)
    color_flood_fill(target, fill, x, y, Magick::FloodfillMethod)
end
color_point(x, y, fill) click to toggle source

Set the color at x,y

# File lib/RMagick.rb, line 793
def color_point(x, y, fill)
    f = copy
    f.pixel_color(x, y, fill)
    return f
end
color_reset!(fill) click to toggle source

Set all pixels to the fill color. Very similar to Image#erase! Accepts either String or Pixel arguments

# File lib/RMagick.rb, line 814
def color_reset!(fill)
    save = background_color
    # Change the background color _outside_ the begin block
    # so that if this object is frozen the exeception will be
    # raised before we have to handle it explicitly.
    self.background_color = fill
    begin
        erase!
    ensure
        self.background_color = save
    end
    self
end
crop_resized(ncols, nrows=nil, gravity=CenterGravity) click to toggle source

Preserve aliases used < RMagick 2.0.1

Alias for: resize_to_fill
crop_resized!(ncols, nrows=nil, gravity=CenterGravity) click to toggle source
Alias for: resize_to_fill!
cur_image() click to toggle source

Used by ImageList methods - see Magick::ImageList#cur_image

# File lib/RMagick.rb, line 829
def cur_image
    self
end
each_iptc_dataset() { |dataset, data_field| ... } click to toggle source

Iterate over IPTC record number:dataset tags, yield for each non-nil dataset

# File lib/RMagick.rb, line 891
def each_iptc_dataset
    Magick::IPTC.constants.each do |record|
        rec = Magick::IPTC.const_get(record)
        rec.constants.each do |dataset|
            data_field = get_iptc_dataset(rec.const_get(dataset))
            yield(dataset, data_field) unless data_field.nil?
        end
    end
    nil
end
each_pixel() { |p, n%columns, n/columns| ... } click to toggle source

Thanks to Russell Norris!

# File lib/RMagick.rb, line 834
def each_pixel
  get_pixels(0, 0, columns, rows).each_with_index do |p, n|
    yield(p, n%columns, n/columns)
  end
  self
end
get_exif_by_entry(*entry) click to toggle source

Retrieve EXIF data by entry or all. If one or more entry names specified, return the values associated with the entries. If no entries specified, return all entries and values. The return value is an array of [name,value] arrays.

# File lib/RMagick.rb, line 845
def get_exif_by_entry(*entry)
    ary = Array.new
    if entry.length == 0
        exif_data = self['EXIF:*']
        if exif_data
            exif_data.split("\n").each { |exif| ary.push(exif.split('=')) }
        end
    else
        get_exif_by_entry()     # ensure properties is populated with exif data
        entry.each do |name|
            rval = self["EXIF:#{name}"]
            ary.push([name, rval])
        end
    end
    return ary
end
get_exif_by_number(*tag) click to toggle source

Retrieve EXIF data by tag number or all tag/value pairs. The return value is a hash.

# File lib/RMagick.rb, line 863
def get_exif_by_number(*tag)
    hash = Hash.new
    if tag.length == 0
        exif_data = self['EXIF:!']
        if exif_data
            exif_data.split("\n").each do |exif|
                tag, value = exif.split('=')
                tag = tag[1,4].hex
                hash[tag] = value
            end
        end
    else
        get_exif_by_number()    # ensure properties is populated with exif data
        tag.each do |num|
            rval = self['#%04X' % num.to_i]
            hash[num] = rval == 'unknown' ? nil : rval
        end
    end
    return hash
end
get_iptc_dataset(ds) click to toggle source

Retrieve IPTC information by record number:dataset tag constant defined in Magick::IPTC, above.

# File lib/RMagick.rb, line 886
def get_iptc_dataset(ds)
    self['IPTC:'+ds]
end
level(black_point=0.0, white_point=nil, gamma=nil) click to toggle source

(Thanks to Al Evans for the suggestion.)

# File lib/RMagick.rb, line 915
def level(black_point=0.0, white_point=nil, gamma=nil)
    black_point = Float(black_point)

    white_point ||= Magick::QuantumRange - black_point
    white_point = Float(white_point)

    gamma_arg = gamma
    gamma ||= 1.0
    gamma = Float(gamma)

    if gamma.abs > 10.0 || white_point.abs <= 10.0 || white_point.abs < gamma.abs
        gamma, white_point = white_point, gamma
        unless gamma_arg
            white_point = Magick::QuantumRange - black_point
        end
    end

    return level2(black_point, white_point, gamma)
end
matte_fill_to_border(x, y) click to toggle source

Make transparent any neighbor pixel that is not the border color.

# File lib/RMagick.rb, line 969
def matte_fill_to_border(x, y)
    f = copy
    f.opacity = Magick::OpaqueOpacity unless f.matte
    f.matte_flood_fill(border_color, TransparentOpacity,
                       x, y, FillToBorderMethod)
end
matte_floodfill(x, y) click to toggle source

Make transparent any pixel that matches the color of the pixel at (x,y) and is a neighbor.

# File lib/RMagick.rb, line 960
def matte_floodfill(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    target = f.pixel_color(x, y)
    f.matte_flood_fill(target, TransparentOpacity,
                       x, y, FloodfillMethod)
end
matte_point(x, y) click to toggle source

Make the pixel at (x,y) transparent.

# File lib/RMagick.rb, line 940
def matte_point(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    pixel = f.pixel_color(x,y)
    pixel.opacity = TransparentOpacity
    f.pixel_color(x, y, pixel)
    return f
end
matte_replace(x, y) click to toggle source

Make transparent all pixels that are the same color as the pixel at (x, y).

# File lib/RMagick.rb, line 951
def matte_replace(x, y)
    f = copy
    f.opacity = OpaqueOpacity unless f.matte
    target = f.pixel_color(x, y)
    f.transparent(target)
end
matte_reset!() click to toggle source

Make all pixels transparent.

# File lib/RMagick.rb, line 977
def matte_reset!
    self.opacity = Magick::TransparentOpacity
    self
end
resample(x_res=72.0, y_res=nil) click to toggle source

Corresponds to ImageMagick’s -resample option

# File lib/RMagick.rb, line 983
def resample(x_res=72.0, y_res=nil)
    y_res ||= x_res
    width = x_res * columns / x_resolution + 0.5
    height = y_res * rows / y_resolution + 0.5
    self.x_resolution = x_res
    self.y_resolution = y_res
    resize(width, height)
end
resize_to_fill(ncols, nrows=nil, gravity=CenterGravity) click to toggle source

Force an image to exact dimensions without changing the aspect ratio. Resize and crop if necessary. (Thanks to Jerett Taylor!)

# File lib/RMagick.rb, line 994
def resize_to_fill(ncols, nrows=nil, gravity=CenterGravity)
    copy.resize_to_fill!(ncols, nrows, gravity)
end
Also aliased as: crop_resized
resize_to_fill!(ncols, nrows=nil, gravity=CenterGravity) click to toggle source
# File lib/RMagick.rb, line 998
def resize_to_fill!(ncols, nrows=nil, gravity=CenterGravity)
    nrows ||= ncols
    if ncols != columns || nrows != rows
        scale = [ncols/columns.to_f, nrows/rows.to_f].max
        resize!(scale*columns+0.5, scale*rows+0.5)
    end
    crop!(gravity, ncols, nrows, true) if ncols != columns || nrows != rows
    self
end
Also aliased as: crop_resized!
resize_to_fit(cols, rows=nil) click to toggle source

Convenience method to resize retaining the aspect ratio. (Thanks to Robert Manni!)

# File lib/RMagick.rb, line 1014
def resize_to_fit(cols, rows=nil)
    rows ||= cols
    change_geometry(Geometry.new(cols, rows)) do |ncols, nrows|
        resize(ncols, nrows)
    end
end
resize_to_fit!(cols, rows=nil) click to toggle source
# File lib/RMagick.rb, line 1021
def resize_to_fit!(cols, rows=nil)
    rows ||= cols
    change_geometry(Geometry.new(cols, rows)) do |ncols, nrows|
        resize!(ncols, nrows)
    end
end
texture_fill_to_border(x, y, texture) click to toggle source

Replace neighboring pixels to border color with texture pixels

# File lib/RMagick.rb, line 1035
def texture_fill_to_border(x, y, texture)
    texture_flood_fill(border_color, texture, x, y, FillToBorderMethod)
end
texture_floodfill(x, y, texture) click to toggle source

Replace matching neighboring pixels with texture pixels

# File lib/RMagick.rb, line 1029
def texture_floodfill(x, y, texture)
    target = pixel_color(x, y)
    texture_flood_fill(target, texture, x, y, FloodfillMethod)
end
view(x, y, width, height) { |view| ... } click to toggle source

Construct a view. If a block is present, yield and pass the view object, otherwise return the view object.

# File lib/RMagick.rb, line 1041
def view(x, y, width, height)
    view = View.new(self, x, y, width, height)

    if block_given?
        begin
            yield(view)
        ensure
            view.sync
        end
        return nil
    else
        return view
    end
end