net.sf.image4j.codec.bmp
Class BMPEncoder

java.lang.Object
  net.sf.image4j.codec.bmp.BMPEncoder

public class BMPEncoder
extends java.lang.Object

Encodes images in BMP format.

Author:

Ian McDonagh

Method Summary

static InfoHeader	createInfoHeader(java.awt.image.BufferedImage img) Creates an InfoHeader from the source image.
static int	getBitmapSize(int w, int h, int bpp) Calculates the size in bytes of a bitmap with the specified size and colour depth.
static int	getBytesPerLine1(int width) Calculates the number of bytes per line required for the given width in pixels, for a 1-bit bitmap.
static int	getBytesPerLine24(int width) Calculates the number of bytes per line required for the given with in pixels, for a 24-bit bitmap.
static int	getBytesPerLine4(int width) Calculates the number of bytes per line required for the given with in pixels, for a 4-bit bitmap.
static int	getBytesPerLine8(int width) Calculates the number of bytes per line required for the given with in pixels, for a 8-bit bitmap.
static int	getColorMapSize(short sBitCount) Calculates the size in bytes for a colour map with the specified bit count.
static void	write(java.awt.image.BufferedImage img, java.io.File file) Encodes and writes BMP data the output file
static void	write(java.awt.image.BufferedImage img, java.io.OutputStream os) Encodes and writes BMP data to the output
static void	write1(java.awt.image.Raster raster, LittleEndianOutputStream out) Encodes and writes raster data as a 1-bit bitmap.
static void	write24(java.awt.image.Raster raster, LittleEndianOutputStream out) Encodes and writes raster data as a 24-bit bitmap.
static void	write32(java.awt.image.Raster raster, java.awt.image.Raster alpha, LittleEndianOutputStream out) Encodes and writes raster data, together with alpha (transparency) data, as a 32-bit bitmap.
static void	write4(java.awt.image.Raster raster, LittleEndianOutputStream out) Encodes and writes raster data as a 4-bit bitmap.
static void	write8(java.awt.image.Raster raster, LittleEndianOutputStream out) Encodes and writes raster data as an 8-bit bitmap.
static void	writeColorMap(java.awt.image.IndexColorModel icm, LittleEndianOutputStream out) Writes the colour map resulting from the source IndexColorModel.
static void	writeFileHeader(int fileSize, int dataOffset, LittleEndianOutputStream out) Writes the file header.

Methods inherited from class java.lang.Object

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

Method Detail

write

public static void write(java.awt.image.BufferedImage img,
                         java.io.File file)
                  throws java.io.IOException

Encodes and writes BMP data the output file

Parameters:

img - the image to encode

file - the file to which encoded data will be written

Throws:

java.io.IOException - if an error occurs

write

public static void write(java.awt.image.BufferedImage img,
                         java.io.OutputStream os)
                  throws java.io.IOException

Encodes and writes BMP data to the output

Parameters:

img - the image to encode

os - the output to which encoded data will be written

Throws:

java.io.IOException - if an error occurs

createInfoHeader

public static InfoHeader createInfoHeader(java.awt.image.BufferedImage img)

Creates an InfoHeader from the source image.

Parameters:

img - the source image

Returns:

the resultant InfoHeader structure

writeFileHeader

public static void writeFileHeader(int fileSize,
                                   int dataOffset,
                                   LittleEndianOutputStream out)
                            throws java.io.IOException

Writes the file header.

Parameters:

fileSize - the calculated file size for the BMP data being written

dataOffset - the calculated offset within the BMP data where the actual bitmap begins

out - the output to which the file header will be written

Throws:

java.io.IOException - if an error occurs

writeColorMap

public static void writeColorMap(java.awt.image.IndexColorModel icm,
                                 LittleEndianOutputStream out)
                          throws java.io.IOException

Writes the colour map resulting from the source IndexColorModel.

Parameters:

icm - the source IndexColorModel

out - the output to which the colour map will be written

Throws:

java.io.IOException - if an error occurs

getBytesPerLine1

public static int getBytesPerLine1(int width)

Calculates the number of bytes per line required for the given width in pixels, for a 1-bit bitmap. Lines are always padded to the next 4-byte boundary.

Parameters:

width - the width in pixels

Returns:

the number of bytes per line

getBytesPerLine4

public static int getBytesPerLine4(int width)

Calculates the number of bytes per line required for the given with in pixels, for a 4-bit bitmap. Lines are always padded to the next 4-byte boundary.

Parameters:

width - the width in pixels

Returns:

the number of bytes per line

getBytesPerLine8

public static int getBytesPerLine8(int width)

Calculates the number of bytes per line required for the given with in pixels, for a 8-bit bitmap. Lines are always padded to the next 4-byte boundary.

Parameters:

width - the width in pixels

Returns:

the number of bytes per line

getBytesPerLine24

public static int getBytesPerLine24(int width)

Calculates the number of bytes per line required for the given with in pixels, for a 24-bit bitmap. Lines are always padded to the next 4-byte boundary.

Parameters:

width - the width in pixels

Returns:

the number of bytes per line

getBitmapSize

public static int getBitmapSize(int w,
                                int h,
                                int bpp)

Calculates the size in bytes of a bitmap with the specified size and colour depth.

Parameters:

w - the width in pixels

h - the height in pixels

bpp - the colour depth (bits per pixel)

Returns:

the size of the bitmap in bytes

write1

public static void write1(java.awt.image.Raster raster,
                          LittleEndianOutputStream out)
                   throws java.io.IOException

Encodes and writes raster data as a 1-bit bitmap.

Parameters:

raster - the source raster data

out - the output to which the bitmap will be written

Throws:

java.io.IOException - if an error occurs

write4

public static void write4(java.awt.image.Raster raster,
                          LittleEndianOutputStream out)
                   throws java.io.IOException

Encodes and writes raster data as a 4-bit bitmap.

Parameters:

raster - the source raster data

out - the output to which the bitmap will be written

Throws:

java.io.IOException - if an error occurs

write8

public static void write8(java.awt.image.Raster raster,
                          LittleEndianOutputStream out)
                   throws java.io.IOException

Encodes and writes raster data as an 8-bit bitmap.

Parameters:

raster - the source raster data

out - the output to which the bitmap will be written

Throws:

java.io.IOException - if an error occurs

write24

public static void write24(java.awt.image.Raster raster,
                           LittleEndianOutputStream out)
                    throws java.io.IOException

Encodes and writes raster data as a 24-bit bitmap.

Parameters:

raster - the source raster data

out - the output to which the bitmap will be written

Throws:

java.io.IOException - if an error occurs

write32

public static void write32(java.awt.image.Raster raster,
                           java.awt.image.Raster alpha,
                           LittleEndianOutputStream out)
                    throws java.io.IOException

Encodes and writes raster data, together with alpha (transparency) data, as a 32-bit bitmap.

Parameters:

raster - the source raster data

alpha - the source alpha data

out - the output to which the bitmap will be written

Throws:

java.io.IOException - if an error occurs

getColorMapSize

public static int getColorMapSize(short sBitCount)

Calculates the size in bytes for a colour map with the specified bit count.

Parameters:

sBitCount - the bit count, which represents the colour depth

Returns:

the size of the colour map, in bytes if sBitCount is less than or equal to 8, otherwise 0 as colour maps are only used for bitmaps with a colour depth of 8 bits or less.