Package digilib.image

Interface DocuImage

All Known Implementing Classes:

DocuImageImpl, ImageInfoDocuImage, ImageLoaderDocuImage

public interface DocuImage

The basic class for the representation of a digilib image. The actual image object is hidden in the class, only methods for loading, manipulation, and saving are exported. This strategy enables implementations using different toolkits that rely on different image base classes (like JIMI, Java2D and JAI).

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	DocuImage.ColorOp	Operations for colorOps.

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)	Crops and scales 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 interpolation 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 of the DocuImage implementation.
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.
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.
void	scale(double scaleX, double scaleY)	Scales the current image.
void	setHacks(String hackString)	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 interpolation quality.
void	setReaderClasses(Map<String,String> typeClassMap)	Set preferred image reader classes.
void	setWriterClasses(Map<String,String> typeClassMap)	Set preferred image writer classes.
void	writeImage(String mt, OutputStream ostream)	Writes the current image to an OutputStream.

Method Detail

loadImage

void loadImage(ImageInput ii)
        throws FileOpException

Loads an image file into the Object.

Parameters:

ii - Image File.

Throws:

FileOpException - Exception thrown if any error occurs.

isSubimageSupported

boolean isSubimageSupported()

This DocuImage supports the loadSubImage operation.

Returns:

if loadSubImage is supported

loadSubimage

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

Load only a subsampled region of the image file.

Parameters:

ii - the ImageInput

region - the region

subsample - the subsample

Throws:

FileOpException - on error

writeImage

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

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.

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

getWidth

int getWidth()

The width of the current image in pixel.

Returns:

Image width in pixels.

getHeight

int getHeight()

The height of the current image in pixel.

Returns:

Image height in pixels.

getSize

ImageSize getSize()

The size of the current image in pixel.

Returns:

the ImageSize

getMimetype

String getMimetype()

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

Returns:

String the mime-type of this image.

crop

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

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.

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

scale

void scale(double scaleX,
           double scaleY)
    throws ImageOpException

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

Parameters:

scaleX - the scaleX

scaleY - the scaleY

Throws:

ImageOpException - on error

cropAndScale

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

Crops and scales 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).

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.

rotate

void rotate(double angle)
     throws ImageOpException

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.

Parameters:

angle - rotation angle in degree

Throws:

ImageOpException - on error

mirror

void mirror(double angle)
     throws ImageOpException

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.

Parameters:

angle - angle of mirror axis

Throws:

ImageOpException - on error

enhance

void enhance(float mult,
             float add)
      throws ImageOpException

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.

Parameters:

mult - multiplicative constant for contrast enhancement

add - additive constant for brightness enhancement

Throws:

ImageOpException - on error

enhanceRGB

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

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.

Parameters:

rgbm - multiplicative constants for red, green, blue

rgba - additive constant for red, green, blue

Throws:

ImageOpException - on error

colorOp

void colorOp(DocuImage.ColorOp op)
      throws ImageOpException

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)

Parameters:

op - the ColorOp

Throws:

ImageOpException - on error

getQuality

int getQuality()

Returns the interpolation quality.

Returns:

int the quality

setQuality

void setQuality(int quality)

Sets the interpolation quality.

Parameters:

quality - The quality to set

dispose

void dispose()

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

identify

ImageInput identify(ImageInput ii)
             throws IOException

Check image size and type and store in ImageInput ii

Parameters:

ii - the ImageInput

Returns:

the ImageInput

Throws:

IOException - on error

getSupportedFormats

Iterator<String> getSupportedFormats()

Returns the list of supported image formats.

Returns:

the list of supported image formats

getAwtImage

Image getAwtImage()

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

Returns:

the Image

getVersion

String getVersion()

returns the version of the DocuImage implementation.

Returns:

the version

setHacks

void setHacks(String hackString)

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!).

Parameters:

hackString - the hackString

getHacksAsString

String getHacksAsString()

Return String representation of implementation specific image hacks.

Returns:

the hackstring

setHint

void setHint(String key,
             Object value)

Set optional image specific hints with additional information.

Parameters:

key - the key

value - the value

getHint

Object getHint(String key)

Returns the image specific hint with the given key.

Parameters:

key - the key

Returns:

the hint

setReaderClasses

void setReaderClasses(Map<String,String> typeClassMap)

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.

Parameters:

typeClassMap -

setWriterClasses

void setWriterClasses(Map<String,String> typeClassMap)

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.

Parameters:

typeClassMap -