com.qoppa.pdfOptimizer

Class ImageOutput

java.lang.Object

com.qoppa.pdfOptimizer.ImageOutput

public class ImageOutput
extends Object

This class describes how an image should be modified. This class holds output image properties, such as compression, color space and image size. When an image is processed, it will look at that image's corresponding ImageOutput object (if there is one) and then modify the image to match.

Author:

Qoppa Software

Field Summary

Fields

Modifier and Type	Field and Description
static int	CO_FLATE Compress image using Flate compression.
static int	CO_JBIG2 Compress image to JBIG2 (implies conversion to B/W).
static int	CO_JPEG Compress image to JPEG.
static int	CO_JPEG2000 Compress image to JPEG 2000.
static int	CO_RETAIN Retain image current compression.
static int	CS_BW Convert image to B/W (1 bit grayscale).
static int	CS_CMYK Convert image to CMYK.
static int	CS_GRAY Convert image to grayscale.
static int	CS_RETAIN Retain image current color space.
static int	CS_RGB Convert image to RGB.

Constructor Summary

Constructors

Constructor and Description
ImageOutput(int imageCompression, float compQuality, int colorSpace, int imgWidth, int imgHeight) Constructs an ImageOuput object with the given image compression, compression quality, color space, width and height.
ImageOutput(int imageCompression, float compQuality, int colorSpace, int imgWidth, int imgHeight, boolean onlyChangeIfSmaller)
ImageOutput(int imageCompression, int colorSpace, int imgWidth, int imgHeight) Constructs an ImageOuput object with the given image compression, color space, width and height.

Method Summary

Modifier and Type	Method and Description
int	getColorSpace() Gets the image output color space.
int	getCompression() Returns the image output compression.
float	getCompressionQuality() Returns the image output compression quality which applies to JPEG and JPEG2000 images.
int	getImageHeight() Returns the image output image width in pixels.
int	getImageWidth() Returns the image output image width in pixels.
boolean	isOnlyChangeIfSmaller() Sets the flag to update an image only when the altered image is smaller than the original.
void	setColorSpace(int cs) Sets the color space to convert images to.
void	setCompression(int compression) Sets the image output compression.
void	setCompressionQuality(float compQuality) Sets the image output compression quality, which is only used when the compression is JPEG or JPEG2000.
void	setImageHeight(int imgHeight) Sets the image output image height in pixels.
void	setImageWidth(int imgWidth) Sets the image output image width in pixels.
void	setOnlyChangeIfSmaller(boolean mOnlyChangeIfSmaller) Sets the flag to update an image only when the altered image is smaller than the original.
String	toString() Display human-readable processing parameters.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

CO_RETAIN

public static final int CO_RETAIN

Retain image current compression.

See Also:

Constant Field Values

CO_JPEG

public static final int CO_JPEG

Compress image to JPEG.

See Also:

Constant Field Values

CO_JPEG2000

public static final int CO_JPEG2000

Compress image to JPEG 2000.

See Also:

Constant Field Values

CO_JBIG2

public static final int CO_JBIG2

Compress image to JBIG2 (implies conversion to B/W).

See Also:

Constant Field Values

CO_FLATE

public static final int CO_FLATE

Compress image using Flate compression.

See Also:

Constant Field Values

CS_RETAIN

public static final int CS_RETAIN

Retain image current color space.

See Also:

Constant Field Values

CS_RGB

public static final int CS_RGB

Convert image to RGB.

See Also:

Constant Field Values

CS_GRAY

public static final int CS_GRAY

Convert image to grayscale.

See Also:

Constant Field Values

CS_CMYK

public static final int CS_CMYK

Convert image to CMYK.

See Also:

Constant Field Values

CS_BW

public static final int CS_BW

Convert image to B/W (1 bit grayscale).

See Also:

Constant Field Values

Constructor Detail

ImageOutput

public ImageOutput(int imageCompression,
                   int colorSpace,
                   int imgWidth,
                   int imgHeight)

Constructs an ImageOuput object with the given image compression, color space, width and height. When the new compression is JPEG or JPEG2000, a default quality of 0.8 (80%) will be used.

Parameters:

imageCompression - the new compression, allowed values are CO_RETAIN, CO_JPEG, CO_JPEG2000, CO_JBIG2, CO_FLATE

colorSpace - the color space to convert to, allowed values are CS_RETAIN, CS_BW, CS_CMYK, CS_GRAY, CS_RGB

imgWidth - the new image width, in pixels

imgHeight - the new image height, in pixels

ImageOutput

public ImageOutput(int imageCompression,
                   float compQuality,
                   int colorSpace,
                   int imgWidth,
                   int imgHeight)

Constructs an ImageOuput object with the given image compression, compression quality, color space, width and height. The compression quality is only used when the compression is JPEG or JPEG2000 and is used to calculate the data rate (bits per pixel). The range for this value is 0.0 to 1.0 with lower values producing higher compression and lower quality. As a guideline, 0.25 is low quality, 0.5 is medium quality and 0.75 is high quality. If a value higher than the lossless compression rate is provided, then making a small change in the value will not make a difference. For example, if a quality of 0.5 produces lossless compression, then anything higher than 0.5 will produce the same results. However using a compression of 0.4 will produce a smaller, lower quality file.

Parameters:

imageCompression - the new compression, allowed values are CO_RETAIN, CO_JPEG, CO_JPEG2000, CO_JBIG2, CO_FLATE

compQuality - the new compression quality, allowed values are 0.1 to 1.0

colorSpace - the color space to convert to, allowed values are CS_RETAIN, CS_BW, CS_CMYK, CS_GRAY, CS_RGB

imgWidth - the new image width, in pixels

imgHeight - the new image height, in pixels

ImageOutput

public ImageOutput(int imageCompression,
                   float compQuality,
                   int colorSpace,
                   int imgWidth,
                   int imgHeight,
                   boolean onlyChangeIfSmaller)

Method Detail

getCompressionQuality

public float getCompressionQuality()

Returns the image output compression quality which applies to JPEG and JPEG2000 images. The range for this value is 0.0 to 1.0. Lower values mean higher compression and lower quality. As a guideline, 0.25 is low quality, 0.5 is medium quality and 0.75 is high quality.

Returns:

the compression quality.

setCompressionQuality

public void setCompressionQuality(float compQuality)

Sets the image output compression quality, which is only used when the compression is JPEG or JPEG2000. The range for this value is 0.0 to 1.0. Lower values mean higher compression and lower quality. As a guideline, 0.25 is low quality, 0.5 is medium quality and 0.75 is high quality. Depending on the quality of the content on the page (JPEG) or the lossless compression rate (JPEG2000), making a small change in the value may not make a difference. For example, if a quality of 0.5 produces lossless compression, then anything higher than 0.5 will produce the same results. However using a compression of 0.4 will produce a smaller, lower quality file.

Parameters:

compQuality - the new value for compression quality. Valid values are 0.1 to 1.0.

getImageWidth

public int getImageWidth()

Returns the image output image width in pixels.

Returns:

the image width.

setImageWidth

public void setImageWidth(int imgWidth)

Sets the image output image width in pixels.

Parameters:

imgWidth - the new image width.

getImageHeight

public int getImageHeight()

Returns the image output image width in pixels.

Returns:

the image height, in pixels.

setImageHeight

public void setImageHeight(int imgHeight)

Sets the image output image height in pixels.

Parameters:

imgHeight - the new image height, in pixels.

toString

public String toString()

Display human-readable processing parameters.

Overrides:

toString in class Object

getCompression

public int getCompression()

Returns the image output compression.

Returns:

the compression

setCompression

public void setCompression(int compression)

Sets the image output compression.

Parameters:

compression - the new compression, allowed values are CO_RETAIN, CO_JPEG, CO_JPEG2000, CO_JBIG2, CO_FLATE

getColorSpace

public int getColorSpace()

Gets the image output color space.

Returns:

The color space.

setColorSpace

public void setColorSpace(int cs)

Sets the color space to convert images to.

Parameters:

cs - The new color space, allowed values are CS_RETAIN, CS_BW, CS_CMYK, CS_GRAY, CS_RGB.

isOnlyChangeIfSmaller

public boolean isOnlyChangeIfSmaller()

Sets the flag to update an image only when the altered image is smaller than the original. The default value is true.

Returns:

Return true if images will only be updated when the altered image is smaller than the original.

setOnlyChangeIfSmaller

public void setOnlyChangeIfSmaller(boolean mOnlyChangeIfSmaller)

Sets the flag to update an image only when the altered image is smaller than the original. The default value is true.

Parameters:

mOnlyChangeIfSmaller - Set to true to update an image only when the altered image is smaller than the original.