Package digilib.image

Class DocuImageImpl

java.lang.Object

digilib.image.DocuImageImpl

All Implemented Interfaces:

DocuImage

Direct Known Subclasses:

ImageInfoDocuImage

public abstract class DocuImageImpl
extends Object
implements DocuImage

Simple abstract implementation of the DocuImage interface. This implementation provides basic functionality for the utility methods like getKnownFileTypes. Image methods like loadImage, writeImage, getWidth, getHeight, crop and scale must be implemented by derived classes.

Nested Class Summary

Nested classes/interfaces inherited from interface digilib.image.DocuImage

DocuImage.ColorOp

Field Summary

Fields

Modifier and Type	Field	Description
static double	epsilon	epsilon for float comparisons.
protected Map<String,Object>	hints	image specific hints
protected ImageSize	imgSize	image size
protected ImageInput	input	ImageInput that was read
protected static org.slf4j.Logger	logger	logger
protected int	quality	Interpolation quality.
static String	version	DocuImage version

Constructor Summary

Constructors

Constructor	Description
DocuImageImpl()

Method Summary

Modifier and Type	Method	Description
void	colorOp(DocuImage.ColorOp op)	Changes the colors of the current image.
void	crop(int xoff, int yoff, int width, int height)	Crops the current image.
void	cropAndScale(int x_off, int y_off, int width, int height, double scale, int qual)	Crop and scale the current image.
void	dispose()	Frees all resources bound to the DocuImage.
void	enhance(float mult, float add)	Enhances brightness and contrast of the current image.
void	enhanceRGB(float[] rgbm, float[] rgba)	Manipulates the colors of the current image.
Image	getAwtImage()	returns the underlying image as java.awt.Image (if possible, or null)
String	getHacksAsString()	Return String representation of implementation specific image hacks.
int	getHeight()	The height of the current image in pixel.
Object	getHint(String key)	Returns the image specific hint with the given key.
String	getMimetype()	The mime-type of the image, i.e.
int	getQuality()	Returns the quality.
ImageSize	getSize()	The size of the current image in pixel.
Iterator<String>	getSupportedFormats()	Returns the list of supported image formats.
String	getVersion()	Returns the version.
int	getWidth()	The width of the current image in pixel.
ImageInput	identify(ImageInput ii)	Check image size and type and store in ImageInput ii
boolean	isSubimageSupported()	This DocuImage supports the loadSubImage operation.
abstract void	loadImage(ImageInput ii)	Loads an image file into the Object.
void	loadSubimage(ImageInput ii, Rectangle region, int subsample)	Load only a subsampled region of the image file.
void	mirror(double angle)	Mirrors the current image.
void	rotate(double angle)	Rotates the current image.
abstract void	scale(double scaleX, double scaleY)	Scales the current image.
void	setHacks(String hacks)	Set implementation specific image hacks.
void	setHint(String key, Object value)	Set optional image specific hints with additional information.
void	setQuality(int quality)	Sets the quality.
void	setReaderClasses(Map<String,String> typeClassMap)	Set preferred image reader classes.
void	setWriterClasses(Map<String,String> typeClassMap)	Set preferred image writer classes.
abstract void	writeImage(String mt, OutputStream ostream)	Writes the current image to an OutputStream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

version

public static final String version

DocuImage version

See Also:

Constant Field Values

logger

protected static final org.slf4j.Logger logger

logger

quality

protected int quality

Interpolation quality.

epsilon

public static final double epsilon

epsilon for float comparisons.

See Also:

Constant Field Values

imgSize

protected ImageSize imgSize

image size

input

protected ImageInput input

ImageInput that was read

hints

protected Map<String,Object> hints

image specific hints

Constructor Detail

DocuImageImpl

public DocuImageImpl()

Method Detail

getVersion

public String getVersion()

Returns the version.

Specified by:

getVersion in interface DocuImage

Returns:

the version

getQuality

public int getQuality()

Returns the quality.

Specified by:

getQuality in interface DocuImage

Returns:

int

setQuality

public void setQuality(int quality)

Sets the quality.

Specified by:

setQuality in interface DocuImage

Parameters:

quality - The quality to set

cropAndScale

public void cropAndScale(int x_off,
                         int y_off,
                         int width,
                         int height,
                         double scale,
                         int qual)
                  throws ImageOpException

Crop and scale the current image. The current image is cropped to a rectangle of width, height at position x_off, y_off. The resulting image is scaled by the factor scale using the interpolation quality qual (0=worst).

Specified by:

cropAndScale in interface DocuImage

Parameters:

x_off - X offset of the crop rectangle in pixel.

y_off - Y offset of the crop rectangle in pixel.

width - Width of the crop rectangle in pixel.

height - Height of the crop rectangle in pixel.

scale - Scaling factor.

qual - Interpolation quality (0=worst).

Throws:

ImageOpException - Exception thrown on any error.

getMimetype

public String getMimetype()

Description copied from interface: DocuImage

The mime-type of the image, i.e. the mime-type of the input that was read.

Specified by:

getMimetype in interface DocuImage

Returns:

String the mime-type of this image.

identify

public ImageInput identify(ImageInput ii)
                    throws IOException

Description copied from interface: DocuImage

Check image size and type and store in ImageInput ii

Specified by:

identify in interface DocuImage

Parameters:

ii - the ImageInput

Returns:

the ImageInput

Throws:

IOException - on error

rotate

public void rotate(double angle)
            throws ImageOpException

Description copied from interface: DocuImage

Rotates the current image. Replaces the current image with a rotated image. The image is rotated around the center by the angle given in degrees [0, 360] clockwise. Image size and aspect ratio are likely to change.

Specified by:

rotate in interface DocuImage

Parameters:

angle - rotation angle in degree

Throws:

ImageOpException - on error

mirror

public void mirror(double angle)
            throws ImageOpException

Description copied from interface: DocuImage

Mirrors the current image. Replaces the current image with a mirrored image. The mirror axis goes through the center of the image and is rotated by angle degrees. Currently only horizontal and vertical mirroring (0 and 90 degree) are supported.

Specified by:

mirror in interface DocuImage

Parameters:

angle - angle of mirror axis

Throws:

ImageOpException - on error

enhance

public void enhance(float mult,
                    float add)
             throws ImageOpException

Description copied from interface: DocuImage

Enhances brightness and contrast of the current image. Replaces the current image with a brightness and contrast enhanced image. Contrast is enhanced by multiplying the pixel value with the constant mult. Brightness is enhanced by adding the constant add to the pixel value. Operation: p1 = (p0*mult)+add.

Specified by:

enhance in interface DocuImage

Parameters:

mult - multiplicative constant for contrast enhancement

add - additive constant for brightness enhancement

Throws:

ImageOpException - on error

isSubimageSupported

public boolean isSubimageSupported()

Description copied from interface: DocuImage

This DocuImage supports the loadSubImage operation.

Specified by:

isSubimageSupported in interface DocuImage

Returns:

if loadSubImage is supported

loadSubimage

public void loadSubimage(ImageInput ii,
                         Rectangle region,
                         int subsample)
                  throws FileOpException

Description copied from interface: DocuImage

Load only a subsampled region of the image file.

Specified by:

loadSubimage in interface DocuImage

Parameters:

ii - the ImageInput

region - the region

subsample - the subsample

Throws:

FileOpException - on error

enhanceRGB

public void enhanceRGB(float[] rgbm,
                       float[] rgba)
                throws ImageOpException

Description copied from interface: DocuImage

Manipulates the colors of the current image. Replaces the current image with a color modified image. For the red, green and blue color channels all pixel values are multiplied by the constant m and added to the constant a. Operation: p1 = (p0*m)+a.

Specified by:

enhanceRGB in interface DocuImage

Parameters:

rgbm - multiplicative constants for red, green, blue

rgba - additive constant for red, green, blue

Throws:

ImageOpException - on error

colorOp

public void colorOp(DocuImage.ColorOp op)
             throws ImageOpException

Description copied from interface: DocuImage

Changes the colors of the current image. Changes the colors of the current image. Operations are instances of ColorOp: GRAYSCALE: cast color image to grayscale NTSC_GRAY: convert color image to grayscale using NTSC formula INVERT: invert colors (every channel separately) MAP_GRAY_BGR: false color image from grayscale (0: blue, 128: green, 255: red)

Specified by:

colorOp in interface DocuImage

Parameters:

op - the ColorOp

Throws:

ImageOpException - on error

dispose

public void dispose()

Description copied from interface: DocuImage

Frees all resources bound to the DocuImage. Things that should be freed are image objects and open files.

Specified by:

dispose in interface DocuImage

getSupportedFormats

public Iterator<String> getSupportedFormats()

Description copied from interface: DocuImage

Returns the list of supported image formats.

Specified by:

getSupportedFormats in interface DocuImage

Returns:

the list of supported image formats

crop

public void crop(int xoff,
                 int yoff,
                 int width,
                 int height)
          throws ImageOpException

Description copied from interface: DocuImage

Crops the current image. Cuts out a region of the size width x height at the offset xoff, yoff from the current image and replaces the current image with the result.

Specified by:

crop in interface DocuImage

Parameters:

xoff - X offset of crop region

yoff - Y offset of crop region

width - width of crop region

height - height of crop region

Throws:

ImageOpException - on error

getAwtImage

public Image getAwtImage()

Description copied from interface: DocuImage

returns the underlying image as java.awt.Image (if possible, or null)

Specified by:

getAwtImage in interface DocuImage

Returns:

the Image

getHeight

public int getHeight()

Description copied from interface: DocuImage

The height of the current image in pixel.

Specified by:

getHeight in interface DocuImage

Returns:

Image height in pixels.

getWidth

public int getWidth()

Description copied from interface: DocuImage

The width of the current image in pixel.

Specified by:

getWidth in interface DocuImage

Returns:

Image width in pixels.

getSize

public ImageSize getSize()

Description copied from interface: DocuImage

The size of the current image in pixel.

Specified by:

getSize in interface DocuImage

Returns:

the ImageSize

loadImage

public abstract void loadImage(ImageInput ii)
                        throws FileOpException

Description copied from interface: DocuImage

Loads an image file into the Object.

Specified by:

loadImage in interface DocuImage

Parameters:

ii - Image File.

Throws:

FileOpException - Exception thrown if any error occurs.

scale

public abstract void scale(double scaleX,
                           double scaleY)
                    throws ImageOpException

Description copied from interface: DocuImage

Scales the current image. Replaces the current image with an image scaled by the factor scale.

Specified by:

scale in interface DocuImage

Parameters:

scaleX - the scaleX

scaleY - the scaleY

Throws:

ImageOpException - on error

writeImage

public abstract void writeImage(String mt,
                                OutputStream ostream)
                         throws ImageOpException,
                                FileOpException

Description copied from interface: DocuImage

Writes the current image to an OutputStream. The image is encoded to the mime-type mt and sent to the output stream ostream. Currently only mime-types "image/jpeg" and "image/png" are supported.

Specified by:

writeImage in interface DocuImage

Parameters:

mt - mime-type of the image to be sent.

ostream - OutputStream where the image is sent.

Throws:

ImageOpException - Exception in other cases.

FileOpException - Exception on sending data

setHacks

public void setHacks(String hacks)

Description copied from interface: DocuImage

Set implementation specific image hacks. Sets static class members. Needs to be called only once per class. Format: comma separated key=value pairs (no spaces!).

Specified by:

setHacks in interface DocuImage

Parameters:

hacks - the hackString

getHacksAsString

public String getHacksAsString()

Description copied from interface: DocuImage

Return String representation of implementation specific image hacks.

Specified by:

getHacksAsString in interface DocuImage

Returns:

the hackstring

setHint

public void setHint(String key,
                    Object value)

Description copied from interface: DocuImage

Set optional image specific hints with additional information.

Specified by:

setHint in interface DocuImage

Parameters:

key - the key

value - the value

getHint

public Object getHint(String key)

Description copied from interface: DocuImage

Returns the image specific hint with the given key.

Specified by:

getHint in interface DocuImage

Parameters:

key - the key

Returns:

the hint

setReaderClasses

public void setReaderClasses(Map<String,String> typeClassMap)

Description copied from interface: DocuImage

Set preferred image reader classes. Configured with a Map containing content-type and class-name. Sets static class members. Needs to be called only once per class.

Specified by:

setReaderClasses in interface DocuImage

setWriterClasses

public void setWriterClasses(Map<String,String> typeClassMap)

Description copied from interface: DocuImage

Set preferred image writer classes. Configured with a Map containing content-type and class-name. Sets static class members. Needs to be called only once per class.

Specified by:

setWriterClasses in interface DocuImage