image.background_color ->
    aString
    image.background_color = aString or aPixel
The image's background color. By default the background color is "white".
A color name.
image.base_columns -> anInteger
The number of columns in the image before any transformations. Get-only.
image.base_filename -> aString
The image's original filename before any transformations. Get-only.
image.base_rows -> anInteger
The number of rows in the image before any transformations. Get-only.
image.blur ->
    aFloat
    image.blur = aFloat
image.border_color ->
    aString
    image.border_color = aString or aPixel
Either a color name or a Pixel object.
A color name.
bounding_box -> aRectangle
The image's bounding box. The bounding box is the rectangle that encloses all the pixels not in the border color. Uses the current fuzz value. Get-only.
In this example, the bounding box is the gray square enclosing the blue circle. (The coordinates and red circles were added after the bounding box was computed.)
image.chromaticity ->
    aChromaticity
    image.chromaticity = aChromaticity
The red, green, blue, and white-point chromaticity values..
image.class_type ->
    aClassType
    image.class_type = aClassType
The image's storage class. If DirectClass then the pixels contain valid RGB or CMYK colors. If PseudoClass then the image has a colormap referenced by the pixel's index member.
A ClassType constant.
A ClassType constant.
image.clip_mask = anImage or anImageList or
    nil
Associates a clip mask with the image. The clip mask must have the same dimensions as the image. Set any pixel component of the clip mask to TransparentOpacity to prevent that corresponding image pixel component from being updated. Set-only.
If an imagelist, uses the current image as the clip mask.
    Assign nil to remove the clip mask.
image.color_profile ->
    aString
    image.color_profile = aString
The ICC color profile.
A color profile is represented as a string.
The current color profile, or nil if there is
    no profile.
image.colors -> anInteger
The number of colors in the colormap. Only meaningful for PseudoClass images. Get-only.
image.colorspace ->
    aColorspace
    image.colorspace = aColorspace
Image pixel interpretation. If the colorspace is RGBColorspace the pixels are red, green, blue. If matte is true, then red, green, blue, and opacity. If it is CMYKColorspace, the pixels are cyan, yellow, magenta, black. Otherwise the colorspace is ignored.
A Colorspace constant.
A Colorspace constant.
image.columns -> anInteger
The width of the image in pixels. Get-only.
image.compose ->
    aCompositeOperator
    image.compose = aCompositeOperator
The image composite operator. The default is OverCompositeOp. See montage.
A composite operator constant.
A composite operator constant.
image.compression ->
    aCompressionType
    image.compression = aCompressionType
A CompressionType constant.
A CompressionType constant.
image.delay ->
    anInteger
    image.delay = anInteger
Time in 1/100ths of a second which must expire before displaying the next image in an animated sequence. The default is 0.
The current delay value.
image.density ->
    aString
    image.density = aString or aGeometry
The vertical and horizontal resolution in pixels of the image. The default is "72x72".
The density may be expressed either as a string or a
    Geometry object. If a
    string, it is in the form "XxY", or simply "X". If "Y" is
    omitted it is set to "X". To specify the density with a
    Geometry object, set the width attribute to the x
    resolution and the height argument to the y
    resolution. If height is nil, width
    will be used as the y resolution as well.
The image density represented as a string.
Also see x_resolution and y_resolution.
image.depth -> anInteger
The image depth (8, 16, or 32). Get-only.
image.directory -> aString
Tile names from within an image montage. Only valid after calling montage or reading a MIFF file which contains a directory. Get-only.
A newline ("\n")-delimited list of the images in the montage.
image.dispose ->
    anInteger
    image.dispose = aDisposeType
GIF disposal method. This attribute is used to control how successive images are rendered (how the preceding image is disposed of) when creating a GIF animation.
An integer corresponding to the disposal method.
image.endian ->
    anEndianType
    image.endian = anEndianType
Get or set the endian attribute. (As best I can tell, only the TIFF format supports this attribute.)
An EndianType value.
An EndianType value.
image.extract_info ->
    aRectangle
    image.extract_info = aRectangle
Specify a rectangle within an image, or retrieve the rectangle specified when the image was constituted. See extract=.
A Rectangle object.
A Rectangle object.
This attribute replaces the tile_info attribute in releases of
    ImageMagick starting with 5.5.6. With releases of ImageMagick
    prior to 5.5.6, this attribute is a synonym for
    tile_info.
image.filename -> aString
The image filename. Get-only.
image.filesize -> anInteger
The image filesize in bytes. Get-only.
image.filter ->
    aFilterType
    image.filter = aFilterType
Filter to use when resizing image. The reduction filter employed has a significant effect on the time required to resize an image and the resulting quality. The default filter is Lanczos which has been shown to produce high quality results when reducing most images.
A FilterType constant.
image.format ->
    aString
    image.format = aString
The image encoding format. For example, "GIF" or "PNG". See formats.
The format name.
The format name.
image.fuzz ->
    aFloat
    image.fuzz = aNumeric or aString
Colors within this distance are considered equal. A number of algorithms search for a target color. By default the color must be exact. Use this [attribute] to match colors that are close to the target color in RGB space.
See opaque, texture_floodfill, and transparent.
The argument may be a floating-point numeric value or a
    string in the form "NN%". In the second case, the argument is
    computed as a percentage of MaxRGB. For
    example, a value of '5%' sets fuzz to
    0.05*MaxRGB.
A Float
image.gamma ->
    aFloat
    image.gamma = aFloat
Gamma level of the image. The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference.
image.geometry ->
    aString
    image.geometry = aString or aGeometry
Preferred size of the image when encoding.
A geometry string or a Geometry object.
image.image_type ->
    anImageType
    image.image_type = anImageType
The image type classification. For example, GrayscaleType. Don't confuse this attribute with the format, that is "GIF" or "JPG".
An ImageType constant.
An ImageType constant.
image.interlace ->
    anInterlaceType
    image.interlace = anInterlaceType
The type of interlacing scheme (default NoInterlace). This option is used to specify the type of interlacing scheme for raw image formats such as RGB or YUV. NoInterlace means do not interlace, LineInterlace uses scanline interlacing, and PlaneInterlace uses plane interlacing. PartitionInterlace is like PlaneInterlace except the different planes are saved to individual files (e.g. image.R, image.G, and image.B). Use LineInterlace or PlaneInterlace to create an interlaced GIF or progressive JPEG image.
An InterlaceType constant.
An InterlaceType constant.
image.iptc_profile ->
    aString
    image.iptc_profile = aString or nil
IPTC profile. Specifications are available from the International Press Telecommunications Council for IPTC profiles.
To remove an existing profile, assign nil to
    the attribute.
The current profile, or nil if the image has no
    IPTC profile.
image.matte -> true
    or false
    image.matte = true or false
If true, honor the opacity values in the image
    pixels. See Pixel.
image.mean_error_per_pixel -> aFloat
The mean error per pixel computed when
    a image is color reduced. This parameter is only valid
    if the verbose argument to quantize[ImageList][Image] is set to true.
    Get-only.
image.mime_type -> aString
Returns the officially registered (or de facto) MIME media-type. If there is no registered media-type, returns "image/x-magick". Get-only.
image.montage ->
    aString
    image.montage = nil
Tile size and offset within an image montage. Only valid for [images produced by montage.] The string is in the form of a geometry string.
To release the montage string, set this attribute to
    nil.
image.normalized_mean_error -> aFloat
The normalized mean error computed
    when an image is color reduced. This parameter is only
    valid if the verbose argument to quantize[ImageList][Image] is set to true.
    Get-only.
image.normalized_maximum_error -> aFloat
The normalized mean error per pixel
    computed when an image is color reduced. This parameter
    is only valid if the verbose argument to
    quantize[ImageList][Image] is set to true.
    Get-only.
image.number_colors -> anInteger
Number of unique colors in the image. Get-only.
image.offset ->
    anInteger
    image.offset = anInteger
Number of initial bytes to skip over when reading raw image.
image.opacity = anInteger
Attenuates the opacity channel of an image. If the image pixels are opaque, they are set to the specified opacity level. Otherwise, the pixel opacity values are blended with the supplied transparency value. Set-only.
image.page ->
    aRectangle
    image.page = aRectangle
When compositing, this attribute describes the position of this image with respect to the underlying image. See coalesce, flatten_images, and mosaic.
A Rectangle object.
A Rectangle object.
image.quantum_depth -> anInteger
The image depth to the nearest Quantum (8, 16, or 32). Get-only. Available in ImageMagick 6.0.0.
image.rendering_intent ->
    aRenderingIntent
    image.rendering_intent = aRenderingIntent
The type of rendering intent.
A RenderingIntent constant.
image.rows -> anInteger
The height of the image in pixels. Get-only.
image.scene -> anInteger
The scene number assigned to the image the last time the
    image was written to a multi-image image file. Don't confuse
    this attribute with ImageList's scene attribute, which denotes the image
    to which Image methods will be sent.
image.start_loop ->
    true or false
    image.start_loop = true or false
Indicates the first image in an animation.
image.tile_info ->
    aRectangle
    image.tile_info = aRectangle
Describes a tile within an image. For example, if your image is 640x480 you may only want 320x256 with an offset of +128+64. It is used for raw formats such as RGB and CMYK as well as for TIFF.
This attribute is deprecated in ImageMagick 5.5.6 and later. Use extract_info instead.
A Rectangle object.
A Rectangle object.
image.total_colors -> anInteger
The number of colors in the image after quantization. Set by
    quantize [ImageList][Image] if the verbose
    argument is true. Get-only.
image.units ->
    aResolutionType
    image.units = aResolutionType
Units of image resolution.
A ResolutionType constant.
A ResolutionType constant.
image.x_resolution ->
    aFloat
    image.x_resolution = aFloat
image.y_resolution ->
    aFloat
    image.y_resolution = aFloat