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Querying

There are a number of operators which retrieve information about an image.

Number ComponentType()

Returns one of the following constants available from the IceComponentType object:

• Fractional: 8 bits per channel, 255 corresponds to 1.0.>
• FixedPoint: 12.4 fixed point format. Nominal range −8.0 to 7.9998. Code value 4096 corresponds to 1.0, and 0 to 0.0.
• Float Single-precision floating point.
• Double: Double-precision floating point.

List DataBox()

Returns a box corresponding to the read/write region of the image. This is the rectangle conventionally thought of as the "image".

List RequestBox()

Returns a box corresponding to the read-only region of the image.

Number Ply()

Returns the number of channels in an image.

Number InputCount()

Returns the number of inputs of a node in an image processing expression.

IceImage GetInput(int i)

i: Index of input desired

Returns the i'th input of a node in an image processing expression.

Bool IsCard()

Returns true if an image is a card (image of constant value), false otherwise.

Number NodeID()

Returns the unique integer identification number of a node.

Sequence Operation()

Returns the operation name of a node.

IceImage SurroundImage()

Returns a reference to the image being used as surround (may be NULL, if the surround image is not set).

Sequence GetChannelPacking()

Returns a string with one character for each channel, intended to represent the meaning of each channel.

Note: The channel packing string is not used in any image processing operation: it is mostly useful when an image with non-standard channel interpretation is read from a file.

Map GetMetaDict()

Returns the meta-data dictionary stored in the image.  Images read in from file will often contain useful information not directly related to image content. Values stored in the dictionary can be retrieved with the following script:

dict := image GetMetaDict
dict foreach(key, value, writeln("the value of ", key, " is ", value)
			

Note: Meta-data dictionaries are not transmitted through image processing nodes. If you need the information in a node, you should retrieve the dictionary and stash it away.

SetMetaDataItem(key, value)

key: Sequence, name of item

value: , thing to be stored.

Store the meta-data value in image's dictionary

GetMetaDataItem(key)

key: Sequence, name of item

Returns the meta-data value stored in the image's dictionary or nil if the key is not found.

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