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 HashMap | tagNameMap |
static int | TAG_JPEG_COMPONENT_DATA_1 the first of a possible 4 color components. |
static int | TAG_JPEG_COMPONENT_DATA_2 the second of a possible 4 color components. |
static int | TAG_JPEG_COMPONENT_DATA_3 the third of a possible 4 color components. |
static int | TAG_JPEG_COMPONENT_DATA_4 the fourth of a possible 4 color components. |
static int | TAG_JPEG_DATA_PRECISION This is in bits/sample, usually 8 (12 and 16 not supported by most software). |
static int | TAG_JPEG_IMAGE_HEIGHT The image's height. |
static int | TAG_JPEG_IMAGE_WIDTH The image's width. |
static 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).
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protected static final HashMap tagNameMap
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.
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.
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.
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.
public static final int TAG_JPEG_DATA_PRECISION
This is in bits/sample, usually 8 (12 and 16 not supported by most software).
public static final int TAG_JPEG_IMAGE_HEIGHT
The image's height. Necessary for decoding the image, so it should always be there.
public static final int TAG_JPEG_IMAGE_WIDTH
The image's width. Necessary for decoding the image, so it should always be there.
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
public JpegDirectory()
Parameters: componentNumber The zero-based index of the component. This number is normally between 0 and 3.
Use getNumberOfComponents for bounds-checking.
Returns:
public int getImageHeight()
public int getImageWidth()
public String getName()
public int getNumberOfComponents()
protected HashMap getTagNameMap()
Copyright © 2006 Drew Noakes. All Rights Reserved.