From 38c0de50ba64eab99ef5a3499505ee39aca1362b Mon Sep 17 00:00:00 2001 From: Frank Baker Date: Thu, 21 Dec 2000 15:29:37 -0500 Subject: [svn-r3179] Purpose: Bringing the Application Developer's Guide into R1.4 (from R1.2) Subdocuments: HDF5 Image and Palette Specification Mapping HDF4 Objects to HDF5 Objects Platforms tested: IE 5 --- doc/html/ADGuide/H4toH5Mapping.pdf | Bin 0 -> 50753 bytes doc/html/ADGuide/ImageSpec.html | 731 +++++++++++++++++++++++++++++++++++ doc/html/ADGuide/PaletteExample1.gif | Bin 0 -> 2731 bytes doc/html/ADGuide/Palettes.fm.anc.gif | Bin 0 -> 4748 bytes 4 files changed, 731 insertions(+) create mode 100644 doc/html/ADGuide/H4toH5Mapping.pdf create mode 100755 doc/html/ADGuide/ImageSpec.html create mode 100755 doc/html/ADGuide/PaletteExample1.gif create mode 100755 doc/html/ADGuide/Palettes.fm.anc.gif diff --git a/doc/html/ADGuide/H4toH5Mapping.pdf b/doc/html/ADGuide/H4toH5Mapping.pdf new file mode 100644 index 0000000..edee66a Binary files /dev/null and b/doc/html/ADGuide/H4toH5Mapping.pdf differ diff --git a/doc/html/ADGuide/ImageSpec.html b/doc/html/ADGuide/ImageSpec.html new file mode 100755 index 0000000..4757b71 --- /dev/null +++ b/doc/html/ADGuide/ImageSpec.html @@ -0,0 +1,731 @@ + + + Palettes + + + + + +

+ + + + +

+ HDF5 documents and links
+ Introduction to HDF5
+ HDF5 Reference Manual
+ +

+
+ HDF5 User's Guide
+ HDF5 Application Developer's Guide +

+ +

+ + + + + + + + + + + +

HDF5 Image and Palette Specification

(Major revision: designated Version 1.1 of the Image and Palette Specification)

+ + +The HDF5 specification defines the standard objects and storage for the +standard HDF5 objects. (For information about the HDF5 library, model and +specification, see the HDF documentation.) This document is an additional +specification do define a standard profile for how to store image data +in HDF5. Image data in HDF5 is stored as HDF5 datasets with standard attributes +to define the properties of the image. +

This specification defines: +

+Standard attributes for an Image dataset
+Standard storage and attributes for Palettes
+Standard for associating Palettes with Images.

+ +

+1. HDF5 Image Specification

+ +

+1.1 Overview

+Image data is stored as an HDF5 dataset with values of HDF5 class Integer +or Float. A common example would be a two dimensional dataset, with +elements of type Integer. However, this specification does not limit +the dimensions or number type that may be used for an Image. +

The dataset for an image is distinguished from other datasets by giving +it an attribute "CLASS=IMAGE". In addition, the Image dataset has +an attribute "PALETTE" that points to one or more palettes. +

A Palette is ha HDF5 dataset. A Pallet dataset has an attribute +"an" and other attributes indicating the type and size of the palette. +A Palette is an independent object, which can be shared among several Image +datasets. +

+1.2 Image Attributes

+ +

+Attribute name="CLASS": +This attribute is of type H5T_C_S1, with size 6.; +For all Images, the value of this attribute is "IMAGE".

+ +

+This attribute identifies this data set as intended to be interpreted as +an image that conforms to the specifications on this page.

+ +

+Attribute name="IMAGE_SUBCLASS": +If present, the value of this attribute indicates the type of Palette that +should be used with the Image. This attribute is of type H5T_C_S1, +with size according to the string. The values are:

+ +

+Attribute name="IMAGE_WHITE_IS_ZERO"

+ +

+This attribute is of type H5T_NATIVE_UCHAR. 0 = false, 1 = true . +This is used for images with IMAGE_SUBCLASS="IMAGE_GRAYSCALE" or "IMAGE_BITMAP".

+ + +

+Attribute name="IMAGE_MINMAXRANGE": +If present, this attribute is an array of two numbers, of the same HDF5 +datatype as the data. The first element is the minimum value of the +data, and the second is the maximum. This is used for images with +IMAGE_SUBCLASS="IMAGE_GRAYSCALE", "IMAGE_BITMAP" or "IMAGE_INDEXED".

+ +

+Attribute name="IMAGE_BACKGROUNDINDEX"

+ +

+If set, this attribute indicates the index value that should be interpreted +as the "background color". This attribute is HDF5 type H5T_NATIVE_UINT.

+ + +

+Attribute name="IMAGE_TRANSPARENCY"

+ +

+If set, this attribute indicates the index value that should be interpreted +as the "transparent color". This attribute is HDF5 type H5T_NATIVE_UINT. +This attribute may not be used for IMAGE_SUBCLASS="IMAGE_TRUE_COLOR".

+ + +

+Attribute name="IMAGE_ASPECTRATIO"

+ +

+If set, this attribute indicates the aspect ratio. This attribute +is HDF5 type H5T_NATIVE_UINT.

+ + +

+Attribute name="IMAGE_COLORMODEL"

+ +

+If set, this attribute indicates the color model of Palette that should +be used with the Image. This attribute is of type H5T_C_S1, with +size 4,5, or 6. The value is one of the color models described in +the Palette specification below. This attribute may be used only +for IMAGE_SUBCLASS="IMAGE_TRUECOLOR" or "IMAGE_INDEXED".

+ + +

+Attribute name="IMAGE_GAMMACORRECTION"

+ +

+If set, this attribute gives the Gamma correction. The type is H5T_NATIVE_FLOAT. +This attribute may be used only for IMAGE_SUBCLASS="IMAGE_TRUECOLOR" or +"IMAGE_INDEXED".

+ + +

+Attribute name="PALETTE"

+ +

+A dataset within an HDF5 file may optionally specify an array of palettes +to be viewed with. The dataset will have an attribute field called "PALETTE" +which contains an array of object reference pointers which refer to palettes +in the file. The first palette in this array will be the default palette +that the data may be viewed with.

+ +Attribute name="IMAGE_VERSION" +

+This attribute is of type H5T_C_S1, with size corresponding to the length +of the version string. This attribute identifies the version number +of this specification to which it conforms. The initial version number +is "1.0".
+"IMAGE_GRAYSCALE",
+"IMAGE_BITMAP",
+"IMAGE_TRUECOLOR",
+"IMAGE_INDEXED"

Attributes of an Image Dataset
Attribute Name		Type	Value
CLASS	R	String	"IMAGE"
PALETTE	O	Array of Object References	<references to Palette datasets>¹
IMAGE_SUBCLASS	O²	String	+ +"IMAGE_GRAYSCALE", + + +"IMAGE_BITMAP", + + +"IMAGE_TRUECOLOR", + + +"IMAGE_INDEXED" +
PALETTE	O	Array of Object Reference	<references to Palette datasets>
IMAGE_WHITE_IS_ZERO	O^3,4	Unsigned Integer	0 = false, 1 = true
IMAGE_MINMAXRANGE	O^3,5	Unsigned Integer[2]	The (<minimum>, <maximum>) value of the data.
IMAGE_BACKGROUNDINDEX	O³	Unsigned Integer	The index of the background color.
IMAGE_TRANSPARENCY	O^3,5	Unsigned Integer	The index of the transparent color.
IMAGE_ASPECTRATIO	O^3,4	Unsigned Integer	The aspect ratio.
IMAGE_COLORMODEL	O^3,6	String	The color model, as defined below in the Palette specification for +attribute PAL_COLORMODEL.
IMAGE_GAMMACORRECTION	O^3,6	Float	The gamma correction.
IMAGE_VERSION	R	String	<specification version number>

+ +

+1.3 Storage Properties for Images

+Image datasets may be stored with any chunking or compression properties +supported by HDF5. +

+2. HDF5 Palette Specification

+ +

+2.1 Overview

+A palette is the means by which color is applied to an image and is also +referred to as a color lookup table. It is a table in which every row contains +the numerical representation of a particular color. In the example of an +8-bit standard RGB color model palette, this numerical representation of +a color is presented as a triplet specifying the intensity of red, green, +and blue components that make up each color. + +

+ +

In this example, the color component numeric type is an 8-bit unsigned +integer. While this is most common and recommended for general use, other +component color numeric datatypes, such as a 16-bit unsigned integer , +may be used. This type is specified as the type attribute of the palette +dataset. (see H5Tget_type(), H5Tset_type()) +

The minimum and maximum values of the component color numeric are specified +as attribute of the palette dataset. See below (attribute PAL_MINMAXNUMERIC). +If these attributes do not exist, it is assumed that the range of values +will fill the space of the color numeric type. i.e. with an 8-bit unsigned +integer, the valid range would be 0 to 255 for each color component. +

The HDF5 palette specification additionally allows for color models +beyond RGB. YUV, HSV, CMY, CMYK, YCbCr color models are supported, and +may be specified as a color model attribute of the palette dataset. (see +"Palette Attributes" for details). +

In HDF 4 and earlier, palettes were limited to 256 colors. The HDF5 +palette specification allows for palettes of varying length. The length +is specified as the number of rows of the palette dataset. +

In a standard palette, the color entries are indexed directly. HDF5 +supports the notion of a range index table. Such a table defines an ascending +ordered of ranges that map dataset values to the palette. If a range index +table exists for the palette, the PAL_TYPE attribute will be set to "RANGEINDEX", +and the PAL_RANGEINDEX attribute will contain an object reference to a +range index table array. If not, the PAL_TYPE attribute either does not +exist, or will be set to "STANDARD". +

The range index table array consists of a one dimensional array with +the same length as the palette dataset - 1. Ideally, the range index would +be of the same type as the dataset it refers to, however this is not a +requirement. +

Example 2: A range index array of type floating point +

+ +

The range index array attribute defines the "to" of the range. +Notice that the range index array attribute is one less entry in size than +the palette. The first entry of 0.1259, specifies that all values below +and up to 0.1259 inclusive, will map to the first palette entry. The second +entry signifies that all values greater than 0.1259 up to 0.3278 inclusive, +will map to the second palette entry, etc. All value greater than the last +range index array attribute (100000) map to the last entry in the palette. +

+2.2. Palette Attributes

+A palette exists in an HDF file as an independent data set with accompanying +attributes. +

These attributes are defined as follows: +

+Attribute name="CLASS": +This attribute is of type H5T_C_S1, with size 8.; +For all palettes, the value of this attribute is "PALETTE". This attribute +identifies this palette data set as a palette that conforms to the specifications +on this page.
+Attribute name="PAL_COLORMODEL": +This attribute is of type H5T_C_S1, with size 4, 5, or 6.; +Possible values for this are "RGB", "YUV", "CMY", "CMYK", "YCbCr", "HSV".; +This defines the color model that the entries in the palette data set represent.
+Attribute name="PAL_TYPE": +This attribute is of type H5T_C_S1, with size 10 or 11.
+Attribute name="PAL_RANGEINDEX": +The PAL_RANGEINDEX attribute contains an HDF object reference pointer +which specifies a range index array in the file to be used for color lookups +for the palette. (Only for PAL_TYPE="RANGEINDEX"
+Attribute name="PAL_MINMAXNUMERIC"

**Attributes of a Palette Dataset**
Attribute Name		Type	Value
CLASS	R	String	"PALETTE"
PAL_COLORMODEL	R	String	Color Model: "RGB", YUV", "CMY", "CMYK", "YCbCr", or "HSV"
PAL_TYPE	R	String	"STANDARD8" or "RANGEINDEX"
RANGE_INDEX	R¹	Object Reference	<Object Reference to Dataset of range index values>
PAL_MINMAXNUMERIC	O	Array[2] of <same datatype as palette>	The first value is the <Minimum value for color values>, the second +value is <Maximum value for color values>²
PAL_VERSION	R	String	<specification version number>

+ +

+2.3. Storage Layout for Palettes

+The values of the Palette are stored as a dataset. The datatype can +be any HDF 5 atomic numeric type. The dataset will have dimensions +(nentries by ncomponents), where 'nentries' +is the number of colors (usually 256) and 'ncomponents' is the +number of values per color (3 for RGB, 4 for CMYK, etc.) +
+

+3. Consistency and Correlation of Image and Palette Attributes

+The objects in this specification are an extension to the base HDF5 specification +and library. They are accessible with the standard HDF5 library, +but the semantics of the objects are not enforced by the base library. +For example, it is perfectly possible to add an attribute called IMAGE +to any dataset, or to include an object reference to any +HDF5 dataset as a "palette" in a PALETTE attribute. this would +be a perfectly valid HDF5 file, but not conformant to this specification. +The rules defined in this specification must be implemented with appropriate +software, and applications must use conforming software to assure correctness. +

The Image and Palette specifications include several mutually redundant +standard attributes, such as the IMAGE_COLORMODEL and the PAL_COLORMODEL. +These attributes are informative not normative, in that it is acceptable +to attach a Palette to an Image dataset even if their attributes do not +match. Software is not required to enforce consistency, and files +may contain mismatched associations of Images and Palettes. In all +cases, it is up to applications to determine what kinds of images and color +models can be supported. +

For example, an Image that was created from a file with an "RGB" may +have a "YUV" Palette in its PALETTE attribute array. This +would be a legal HDF5 file and also a conforms to this specification, although +it may or may not be correct or useable for a given application. +

+ + + + + + + + + + + + +

+ + + + +

+ HDF5 documents and links
+ Introduction to HDF5
+ HDF5 Reference Manual
+ +

+
+ HDF5 User's Guide
+ HDF5 Application Developer's Guide +

+ + + + +

+HDF Help Desk +

+ + + +Last modified: 2 June 2000 + + +
+Describes HDF5 Release 1.4 Beta, December 2000 + + + + diff --git a/doc/html/ADGuide/PaletteExample1.gif b/doc/html/ADGuide/PaletteExample1.gif new file mode 100755 index 0000000..8694d9d Binary files /dev/null and b/doc/html/ADGuide/PaletteExample1.gif differ diff --git a/doc/html/ADGuide/Palettes.fm.anc.gif b/doc/html/ADGuide/Palettes.fm.anc.gif new file mode 100755 index 0000000..d344c03 Binary files /dev/null and b/doc/html/ADGuide/Palettes.fm.anc.gif differ -- cgit v0.12