Extending TiffImages.jl

mutable struct TiffFile{O<:Unsigned, S<:FileIO.Stream}

-> TiffFile

Wrap io with helper parameters to keep track of file attributes.

• uuid: A unique identifier for this file

• filepath: The relative path to this file

• io: The file stream

• first_offset: Location of the first IFD in the file stream

• need_bswap: Whether this file has a different endianness than the host computer

struct IFD{O<:Unsigned}

An image file directory is a sorted collection of the tags representing this plane in the TIFF file. They behave like dictionaries except that tags aren't required to be unique, so given an IFD called ifd, we can add new tags as follows:

julia> ifd[TiffImages.IMAGEDESCRIPTION] = "Some details";

julia> ifd[TiffImages.IMAGEWIDTH] = 512;

julia> ifd
IFD, with tags:
	Tag(IMAGEWIDTH, 512)
	Tag(IMAGEDESCRIPTION, "Some details")

struct Tag{T}

In-memory representation of Tiff Tags, which are essentially key value pairs. The data field can either be a String, a Number, an Array of bitstypes, or a RemoteData type.

• tag

• data

A wrapper to force getindex to return the underlying array instead of only the first element. Usually the first element is sufficient, but sometimes access to the array is needed (to add duplicate entries or access them).

julia> using TiffImages: Iterable

julia> ifd[TiffImages.IMAGEDESCRIPTION] = "test"
"test"

julia> ifd[Iterable(TiffImages.IMAGEDESCRIPTION)] # since wrapped with Iterable, returns array
1-element Vector{TiffImages.Tag}:
 Tag(IMAGEDESCRIPTION, "test")

julia> ifd[Iterable(TiffImages.IMAGEDESCRIPTION)] = "test2" # since wrapped with Iterable, it appends
"test2"

julia> ifd
IFD, with tags:
	Tag(IMAGEDESCRIPTION, "test")
	Tag(IMAGEDESCRIPTION, "test2")

RemoteData

A placeholder type to describe the location and properties of remote data that is too large to fit directly in a tag's spot in the IFD. Calling TiffImages.load! on an IFD object replaces all RemoteDatas with the respective data.

• position: Position of this data in the stream

• count: The length of the data

load!(tf, ifd)

Updates an TiffImages.IFD by replacing all instances of the placeholder type TiffImages.RemoteData with the actual data from the file tf.

sizeof(file)

Number of bytes that file's header will use on disk

sizeof(tag::TiffImages.Tag)

Minimum number of bytes that the data in tag will use on disk.

sizeof(ifd)

Number of bytes that an IFD will use on disk.