# class Image - Attribute accessors

### Table Of Contents

- background_color
- base_columns
- base_filename
- base_rows
- blur
- border_color
- bounding_box
- chromaticity
- class_type
- clip_mask
- color_profile
- colors
- colorspace
- columns
- compose
- compression
- delay
- density
- depth
- directory
- dispose
- filename
- filesize
- filter
- format
- fuzz
- gamma
- geometry
- image_type
- interlace
- iptc_profile
- matte
- matte_color
- mean_error_per_pixel
- montage
- normalized_mean_error
- normalized_maximum_error
- number_colors
- offset
- opacity
- page
- rendering_intent
- rows
- scene
- start_loop
- tile_info
- total_colors
- units
- x_resolution
- y_resolution

background_color background_color= | image.background_color -> aString image.background_color = aString image.background_color = aPixel
| The image's background color expressed as a color name or a Pixel object. By default the background color is "white".
base_columns | image.base_columns -> anInteger
| The number of columns in the image before any transformations.
base_filename | image.base_filename -> aString
| The image's original filename before any transformations.
base_rows | image.base_rows -> anInteger
| The number of rows in the image before any transformations.
blur blur= | image.blur -> aFloat image.blur = aFloat
| The blur factor to use when resizing. See resize.
border_color border_color= | image.border_color -> aString image.border_color = aString image.border_color = aPixel
| The image's border color expressed as a color name or a Pixel object. The default border color is "#dfdfdf" (gray).
bounding_box | image.bounding_box -> aRectangle

The image's bounding box. The bounding box is the rectangle that encloses all the pixels not in the border color. 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.) The return value is a rectangle. |

chromaticity chromaticity= | image.chromaticity -> aChromaticity image.chromaticity = aChromaticity
| The red, green, blue, and white-point chromaticity values. See Chromaticity
class_type class_type= | 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. See ClassType.
clip_mask= | image.clip_mask = anImage image.clip_mask = anImage image.clip_mask = `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. If the assigned object is an imagelist, uses the current image as the clip mask. Assign `nil` to remove the clip mask.
color_profile color_profile= | image.color_profile -> aString image.color_profile = aString
| The ICC color profile.
colors | image.colors -> anInteger
| The number of colors in the colormap. Only meaningful for PseudoClass images.
colorspace colorspace= | 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.
columns | image.columns -> anInteger
| The width of the image.
compose compose= | image.compose -> aCompositeOperator image.compose = aCompositeOperator
| Image composite operator. The default is OverCompositeOp.
compression compression= | image.compression -> aCompressionType image.compression = aCompressionType
| Image compression type. The default is the compression type of the specified image file.
delay delay= | image.delay -> anInteger image.delay = anInteger
| Time in 1/100ths of a second (0 to 65535) which must expire before displaying the next image in an animated sequence. The default is 0.
density density= | image.density -> aString image.density = aString
| The vertical and horizontal resolution in pixels of the image. The density is a string in the form "XxY", or simply "X". If "Y" is omitted it is set to "X". The default is "72x72". Also see x_resolution and y_resolution.
depth | image.depth -> anInteger
| The image depth (8 or 16).
directory | image.directory -> aString
| Tile names from within an image montage. Only valid after calling Image#montage or reading a MIFF file which contains a directory.
dispose dispose= | image.dispose -> anInteger image.dispose = 1, 2, 3, or 4
| 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.
filename | image.filename -> aString
| The image filename.
filesize | image.filesize -> anInteger
| The image filesize in bytes.
filter filter= | 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.
format | image.format -> aString
| The encoding format. For example, "GIF" or "PNG".
fuzz fuzz= | image.fuzz -> aFloat image.fuzz = aFloat
| 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 option to match colors that are close to the target color in RGB space. See the opaque, texture_floodfill, and transparent methods.
gamma gamma= | 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.
geometry geometry= | image.geometry -> aString image.geometry = aString
| Preferred size of the image when encoding. See The geometry string.
image_type image_type= | 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".
interlace interlace= | 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.

See InterlaceType.

iptc_profile iptc_profile= | image.iptc_profile -> aString image.iptc_profile = aString image.iptc_profile = `nil`
| IPTC profile. Specifications are available from the International Press Telecommunications Council for IPTC profiles. To remove an existing profile, assign `nil` to the iptc_profile attribute.
matte matte= | image.matte -> `true` or `false` image.matte = `true` or `false`
| If `true`, honor the opacity values in the image pixels. See Pixel.
matte_color matte_color= | image.matte_color -> aString image.matte_color = aString image.matte_color = aPixel
| The matte color. Specify a color name or a Pixel object. By default, "#bdbdbd".
mean_error_per_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 or Image#quantize is set to true.
montage montage= | image.montage -> aString image.montage = aString
| Tile size and offset within an image montage. Only valid for montage images. The string is in the form of a geometry string. See ImageList#montage.
normalized_mean_error | image.normalized_mean_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 or Image#quantize is set to true.
normalized_maximum_error | 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 or Image#quantize is set to true.
number_colors | image.number_colors -> anInteger
| Number of unique colors in the image.
offset offset= | image.offset -> anInteger image.offset = anInteger
| Number of initial bytes to skip over when reading raw image.
opacity= | image.opacity = anInteger
| A number between 0 and MaxRGB. 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. Note: there is no equivalent reader method.
page page= | image.page -> aRectangle image.page = aRectangle
| When compositing, this attribute describes the position of this image with respect to the underlying image. See ImageList#coalesce, ImageList#flatten_images, and ImageList#mosaic. See Rectangle.
rendering_intent rendering_intent= | image.rendering_intent -> aRenderingIntent image.rendering_intent = aRenderingIntent
| The type of rendering intent. See RenderingIntent.
rows | image.rows -> anInteger
| The height of the image.
scene | 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 the ImageList#scene attribute, which denotes the image to which Image methods will be sent.
start_loop start_loop= | image.start_loop -> `true` or `false` image.start_loop = `true` or `false`
| Indicates the first image in an animation.
tile_info tile_info= | 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. See Rectangle.
total_colors | image.total_colors -> anInteger
| Set by quantize and Image#quantize, if the verbose argument is `true`. The number of colors in the image.
units units= | image.units -> aResolutionType image.units = aResolutionType
| Units of image resolution. See ResolutionType.
x_resolution x_resolution= | image.x_resolution -> aFloat image.x_resolution = aFloat
| Horizontal resolution of the image.
y_resolution y_resolution= | image.y_resolution -> aFloat image.y_resolution = aFloat
| Vertical resolution of the image.