com.drew.metadata.jpeg

Class JpegDirectory

public class JpegDirectory extends Directory

Directory of tags and values for the SOF0 Jpeg segment. This segment holds basic metadata about the image.

Author: Darrell Silver http://www.darrellsilver.com and Drew Noakes

Field Summary
protected static HashMaptagNameMap
static intTAG_JPEG_COMPONENT_DATA_1
the first of a possible 4 color components.
static intTAG_JPEG_COMPONENT_DATA_2
the second of a possible 4 color components.
static intTAG_JPEG_COMPONENT_DATA_3
the third of a possible 4 color components.
static intTAG_JPEG_COMPONENT_DATA_4
the fourth of a possible 4 color components.
static intTAG_JPEG_DATA_PRECISION
This is in bits/sample, usually 8 (12 and 16 not supported by most software).
static intTAG_JPEG_IMAGE_HEIGHT
The image's height.
static intTAG_JPEG_IMAGE_WIDTH
The image's width.
static intTAG_JPEG_NUMBER_OF_COMPONENTS
Usually 1 = grey scaled, 3 = color YcbCr or YIQ, 4 = color CMYK Each component TAG_COMPONENT_DATA_[1-4], has the following meaning: component Id(1byte)(1 = Y, 2 = Cb, 3 = Cr, 4 = I, 5 = Q), sampling factors (1byte) (bit 0-3 vertical., 4-7 horizontal.), quantization table number (1 byte).
Constructor Summary
JpegDirectory()
Method Summary
JpegComponentgetComponent(int componentNumber)
intgetImageHeight()
intgetImageWidth()
StringgetName()
intgetNumberOfComponents()
protected HashMapgetTagNameMap()

Field Detail

tagNameMap

protected static final HashMap tagNameMap

TAG_JPEG_COMPONENT_DATA_1

public static final int TAG_JPEG_COMPONENT_DATA_1
the first of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

TAG_JPEG_COMPONENT_DATA_2

public static final int TAG_JPEG_COMPONENT_DATA_2
the second of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

TAG_JPEG_COMPONENT_DATA_3

public static final int TAG_JPEG_COMPONENT_DATA_3
the third of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

TAG_JPEG_COMPONENT_DATA_4

public static final int TAG_JPEG_COMPONENT_DATA_4
the fourth of a possible 4 color components. Number of components specified in TAG_JPEG_NUMBER_OF_COMPONENTS.

TAG_JPEG_DATA_PRECISION

public static final int TAG_JPEG_DATA_PRECISION
This is in bits/sample, usually 8 (12 and 16 not supported by most software).

TAG_JPEG_IMAGE_HEIGHT

public static final int TAG_JPEG_IMAGE_HEIGHT
The image's height. Necessary for decoding the image, so it should always be there.

TAG_JPEG_IMAGE_WIDTH

public static final int TAG_JPEG_IMAGE_WIDTH
The image's width. Necessary for decoding the image, so it should always be there.

TAG_JPEG_NUMBER_OF_COMPONENTS

public static final int TAG_JPEG_NUMBER_OF_COMPONENTS
Usually 1 = grey scaled, 3 = color YcbCr or YIQ, 4 = color CMYK Each component TAG_COMPONENT_DATA_[1-4], has the following meaning: component Id(1byte)(1 = Y, 2 = Cb, 3 = Cr, 4 = I, 5 = Q), sampling factors (1byte) (bit 0-3 vertical., 4-7 horizontal.), quantization table number (1 byte).

This info is from http://www.funducode.com/freec/Fileformats/format3/format3b.htm

Constructor Detail

JpegDirectory

public JpegDirectory()

Method Detail

getComponent

public JpegComponent getComponent(int componentNumber)

Parameters: componentNumber The zero-based index of the component. This number is normally between 0 and 3. Use getNumberOfComponents for bounds-checking.

Returns:

getImageHeight

public int getImageHeight()

getImageWidth

public int getImageWidth()

getName

public String getName()

getNumberOfComponents

public int getNumberOfComponents()

getTagNameMap

protected HashMap getTagNameMap()
Copyright © 2006 Drew Noakes. All Rights Reserved.