net.sourceforge.jiu.color.reduction

Class AutoDetectColorType


public class AutoDetectColorType
extends Operation

Detects the minimum (in terms of memory) color type of an image. Can convert the original image to that new input type on demand.

Input parameters: image to be examined, boolean that specifies whether conversion will be performed (default is true, conversion is performed). Output parameters: converted image, boolean that expresses whether a conversion was possible.

Supported types for input image: RGB24Image, Gray8Image, Paletted8Image.

BilevelImage is not supported because there is no smaller image type, so bilevel images cannot be reduced.

This operation is not a ImageToImageOperation because this class need not necessarily produce a new image (with setConversion(boolean)(false)).

Usage example

This code snippet loads an image and attempts to reduce it to the minimum color type that will hold it.
 PixelImage image = ImageLoader.load("test.bmp");
 AutoDetectColorType op = new AutoDetectColorType();
 op.setInputImage(image);
 op.process();
 if (op.isReducible())
 {
   image = op.getOutputImage();
 }
 
Author:
Marco Schmidt

Field Summary

static int
TYPE_BILEVEL
static int
TYPE_GRAY16
static int
TYPE_GRAY8
static int
TYPE_PALETTED8
static int
TYPE_RGB24
static int
TYPE_RGB48
static int
TYPE_UNKNOWN
private boolean
doConvert
private Histogram3D
hist
private PixelImage
inputImage
private PixelImage
outputImage
private int
type

Fields inherited from class net.sourceforge.jiu.ops.Operation

abort, progressListeners

Constructor Summary

AutoDetectColorType()
This constructor creates two internal empty lists for progress listeners and parameters.

Method Summary

private void
createBilevelFromGrayOrRgb(IntegerImage in)
Creates a bilevel image from any grayscale (or RGB) image that has been checked to be bilevel.
private void
createBilevelFromPaletted(Paletted8Image in)
private void
createGray8FromGray16(Gray16Image in)
private void
createGray8FromPaletted8(Paletted8Image in, Gray8Image out)
private void
createGrayFromRgb(IntegerImage in, IntegerImage out)
private void
createPaletted8FromRgb24(RGB24Image in)
private void
createPaletted8FromRgb48(RGB48Image in)
private void
createRgb24FromRgb48(RGB48Image in, RGB24Image out)
PixelImage
getOutputImage()
Returns the reduced output image if one was created in process().
int
getType()
Returns the type of the minimum image type found (one of the TYPE_xyz constants of this class).
private boolean
isGray16Gray8(Gray16Image in)
private boolean
isGrayBilevel(IntegerImage in)
boolean
isReducible()
This method can be called after process() to find out if the input image in fact can be reduced to a "smaller" image type.
private boolean
isRgb24Paletted8(RGB24Image in)
private boolean
isRgb48Gray8(RGB48Image in)
private boolean
isRgb48Paletted8(RGB48Image in)
Assumes that it has already been verified that the input 48 bpp RGB image is also a 24 bpp RGB image.
private boolean
isRgb48Rgb24(RGB48Image in)
private boolean
isRgbBilevel(IntegerImage in)
private boolean
isRgbGray(RGBIntegerImage in)
Returns if the input RGB image can be losslessly converted to a grayscale image.
void
process()
This method does the actual work of the operation.
void
setConversion(boolean convert)
This method can be used to specify whether the input image is to be converted to the minimum image type if it is clear that such a conversion is possible.
void
setInputImage(PixelImage image)
This method must be used to specify the mandatory input image.

Methods inherited from class net.sourceforge.jiu.ops.Operation

addProgressListener, addProgressListeners, getAbort, process, removeProgressListener, setAbort, setProgress, setProgress

Field Details

TYPE_BILEVEL

public static final int TYPE_BILEVEL
Field Value:
0

TYPE_GRAY16

public static final int TYPE_GRAY16
Field Value:
4

TYPE_GRAY8

public static final int TYPE_GRAY8
Field Value:
1

TYPE_PALETTED8

public static final int TYPE_PALETTED8
Field Value:
2

TYPE_RGB24

public static final int TYPE_RGB24
Field Value:
3

TYPE_RGB48

public static final int TYPE_RGB48
Field Value:
5

TYPE_UNKNOWN

public static final int TYPE_UNKNOWN
Field Value:
-1

doConvert

private boolean doConvert

hist

private Histogram3D hist

inputImage

private PixelImage inputImage

outputImage

private PixelImage outputImage

type

private int type

Constructor Details

AutoDetectColorType

public AutoDetectColorType()
This constructor creates two internal empty lists for progress listeners and parameters.

Method Details

createBilevelFromGrayOrRgb

private void createBilevelFromGrayOrRgb(IntegerImage in)
Creates a bilevel image from any grayscale (or RGB) image that has been checked to be bilevel.

createBilevelFromPaletted

private void createBilevelFromPaletted(Paletted8Image in)

createGray8FromGray16

private void createGray8FromGray16(Gray16Image in)

createGray8FromPaletted8

private void createGray8FromPaletted8(Paletted8Image in,
                                      Gray8Image out)

createGrayFromRgb

private void createGrayFromRgb(IntegerImage in,
                               IntegerImage out)

createPaletted8FromRgb24

private void createPaletted8FromRgb24(RGB24Image in)

createPaletted8FromRgb48

private void createPaletted8FromRgb48(RGB48Image in)

createRgb24FromRgb48

private void createRgb24FromRgb48(RGB48Image in,
                                  RGB24Image out)

getOutputImage

public PixelImage getOutputImage()
Returns the reduced output image if one was created in process().
Returns:
newly-created output image

getType

public int getType()
Returns the type of the minimum image type found (one of the TYPE_xyz constants of this class). Can only be called after a successful call to process.

isGray16Gray8

private boolean isGray16Gray8(Gray16Image in)

isGrayBilevel

private boolean isGrayBilevel(IntegerImage in)

isReducible

public boolean isReducible()
This method can be called after process() to find out if the input image in fact can be reduced to a "smaller" image type. If this method returns true and if conversion was desired by the user (can be specified via setConversion(boolean)), the reduced image can be retrieved via getOutputImage().
Returns:
if image was found to be reducible in process()

isRgb24Paletted8

private boolean isRgb24Paletted8(RGB24Image in)

isRgb48Gray8

private boolean isRgb48Gray8(RGB48Image in)

isRgb48Paletted8

private boolean isRgb48Paletted8(RGB48Image in)
Assumes that it has already been verified that the input 48 bpp RGB image is also a 24 bpp RGB image.
Parameters:
in - input image to be checked
Returns:
if this image can be losslessly converted to a Paletted8Image

isRgb48Rgb24

private boolean isRgb48Rgb24(RGB48Image in)

isRgbBilevel

private boolean isRgbBilevel(IntegerImage in)

isRgbGray

private boolean isRgbGray(RGBIntegerImage in)
Returns if the input RGB image can be losslessly converted to a grayscale image.
Parameters:
in - RGB image to be checked
Returns:
true if input is gray, false otherwise

process

public void process()
            throws MissingParameterException,
                   WrongParameterException
This method does the actual work of the operation. It must be called after all parameters have been given to the operation object.
Overrides:
process in interface Operation
Throws:
WrongParameterException - if at least one of the input parameters was not initialized appropriately (values out of the valid interval, etc.)
MissingParameterException - if any mandatory parameter was not given to the operation

setConversion

public void setConversion(boolean convert)
This method can be used to specify whether the input image is to be converted to the minimum image type if it is clear that such a conversion is possible. The default value is true. If this is set to false, it can still be
Parameters:
convert - if true, the conversion will be performed

setInputImage

public void setInputImage(PixelImage image)
This method must be used to specify the mandatory input image.
Parameters:
image - PixelImage object to be examined