| java.lang.Object
 javax.imageio.plugins.jpeg.JPEGQTable
| JPEGQTable | | public class JPEGQTable (Code) | | A class encapsulating a single JPEG quantization table.
The elements appear in natural order (as opposed to zig-zag order).
Static variables are provided for the "standard" tables taken from
Annex K of the JPEG specification, as well as the default tables
conventionally used for visually lossless encoding.
For more information about the operation of the standard JPEG plug-in,
see the JPEG
metadata format specification and usage notes
|
| Field Summary | |
| final public static JPEGQTable | K1Div2Luminance
The sample luminance quantization table given in the JPEG
specification, table K.1, with all elements divided by 2.
According to the specification, these values produce "very good"
quality output. | | final public static JPEGQTable | K1Luminance
The sample luminance quantization table given in the JPEG
specification, table K.1. | | final public static JPEGQTable | K2Chrominance
The sample chrominance quantization table given in the JPEG
specification, table K.2. | | final public static JPEGQTable | K2Div2Chrominance
The sample chrominance quantization table given in the JPEG
specification, table K.1, with all elements divided by 2.
According to the specification, these values produce "very good"
quality output. |
| Constructor Summary | |
| public | JPEGQTable(int[] table)
Constructs a quantization table from the argument, which must
contain 64 elements in natural order (not zig-zag order). |
| Method Summary | |
| public JPEGQTable | getScaledInstance(float scaleFactor, boolean forceBaseline)
Returns a new quantization table where the values are multiplied
by scaleFactor and then clamped to the range 1..32767
(or to 1..255 if forceBaseline is true). | | public int[] | getTable()
Returns a copy of the current quantization table as an array
of
int s in natural (not zig-zag) order. | | public String | toString()
Returns a
String representing this quantization table. |
| K1Div2Luminance | | final public static JPEGQTable K1Div2Luminance(Code) | | The sample luminance quantization table given in the JPEG
specification, table K.1, with all elements divided by 2.
According to the specification, these values produce "very good"
quality output. This is the table usually used for "visually lossless"
encoding, and is the default luminance table used if the default
tables and quality settings are used.
See Also: JPEGQTable.K1Luminance |
| K1Luminance | | final public static JPEGQTable K1Luminance(Code) | | The sample luminance quantization table given in the JPEG
specification, table K.1. According to the specification,
these values produce "good" quality output.
See Also: JPEGQTable.K1Div2Luminance |
| K2Chrominance | | final public static JPEGQTable K2Chrominance(Code) | | The sample chrominance quantization table given in the JPEG
specification, table K.2. According to the specification,
these values produce "good" quality output.
See Also: JPEGQTable.K2Div2Chrominance |
| K2Div2Chrominance | | final public static JPEGQTable K2Div2Chrominance(Code) | | The sample chrominance quantization table given in the JPEG
specification, table K.1, with all elements divided by 2.
According to the specification, these values produce "very good"
quality output. This is the table usually used for "visually lossless"
encoding, and is the default chrominance table used if the default
tables and quality settings are used.
See Also: JPEGQTable.K2Chrominance |
| JPEGQTable | | public JPEGQTable(int[] table)(Code) | | Constructs a quantization table from the argument, which must
contain 64 elements in natural order (not zig-zag order).
A copy is made of the the input array.
Parameters:
table - the quantization table, as an int array.
throws:
IllegalArgumentException - if table isnull or table.length is not equal to 64. |
| getScaledInstance | | public JPEGQTable getScaledInstance(float scaleFactor, boolean forceBaseline)(Code) | | Returns a new quantization table where the values are multiplied
by scaleFactor and then clamped to the range 1..32767
(or to 1..255 if forceBaseline is true).
Values of scaleFactor less than 1 tend to improve
the quality level of the table, and values greater than 1.0
degrade the quality level of the table.
Parameters:
scaleFactor - multiplication factor for the table.
Parameters:
forceBaseline - if true,the values will be clamped to the range 1..255 a new quantization table that is a linear multipleof the current table. |
| getTable | | public int[] getTable()(Code) | | Returns a copy of the current quantization table as an array
of
int s in natural (not zig-zag) order.
A copy of the current quantization table. |
| toString | | public String toString()(Code) | | Returns a
String representing this quantization table.
a String representing this quantization table. |
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