I wrote a imagebuffer to BMP flow code snippet, I hope to be useful to everyone.

try {
BufferedImage bi = null;
if (Isurl = = True) {
BI = imageio.read (new URL (Infilename));
}
else {
BI = imageio.read (new File (Infilename));
}

int[] Rgbarray = new int[101 * 29];//The pixel value of the image file I tested is 101 wide and 29 long

Bi.getrgb (0, 0, Rgbarray, 0, 101);
for (int i = 0; i < i++) {//All I do is double color, so here we find out if each pixel is 1 (black) or 0 (white)
if ((Rgbarray[i] & 0xffffff) = = 0x000000)
Rgbarray[i] = 0;
Else
Rgbarray[i] = 1;
}
The following is a BMP file format definition, more specific instructions can be found in the http://www.wotsit.org
Int[] Identifier = {' B ', ' M '};
Int[] FileSize = {0x0e, 0x02, 0x00, 0x00};
int[] reserved = {0x00, 0x00, 0x00, 0x00};
Int[] Bitmapdataoffset = {0x3e, 0x00, 0x00, 0x00};
Int[] Bitmapheadersize = {0x28, 0x00, 0x00, 0x00};
int[] width = {0x65, 0x00, 0x00, 0x00};
int[] height = {0x1d, 0x00, 0x00, 0x00};
Int[] planes = {0x01, 0x00};
Int[] BitsPerPixel = {0x01, 0x00};
Int[] Compression = {0x00, 0x00, 0x00, 0x00};
Int[] Bitmapdatasize = {0xd0, 0x01, 0x00, 0x00};
Int[] Hresolution = {0x00, 0x00, 0x00, 0x00};
Int[] Vresolution = {0x00, 0x00, 0x00, 0x00};
int[] Colors = {0x00, 0x00, 0x00, 0x00};
Int[] Importantcolors = {0x00, 0x00, 0x00, 0x00};
Int[] palette = {0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0x00};
Remember that BMP does not have a scan line to expand to the next 4bytes multiples, such as 101 will become 128, expanded byte 0 can
int[] BitmapData = new int[(101 + 27) * 29/8];
int n = 0;
for (int i = 0; i < i++) {The//bmp format starts at the last line scan
for (int j = 1; J <= + j) {
if (rgbarray[(28-i) * + j-1] = = 1) {
Bitmapdata[n] = Bitmapdata[n] | (1 << (8-j% 8)% 8);
}
if (j% 8 = 0) {
n++;
}
if (j = = 101) {
n + 4;
}
}
}
Randomaccessfile o = new Randomaccessfile (outfilename, "RW");
O.setlength (0);
for (int i = 0; i < identifier.length; i++) {
O.write (Identifier[i]);
}
for (int i = 0; i < filesize.length; i++) {
O.write (Filesize[i]);
}
for (int i = 0; i < reserved.length; i++) {
O.write (Reserved[i]);
}
for (int i = 0; i < bitmapdataoffset.length; i++) {
O.write (Bitmapdataoffset[i]);
}
for (int i = 0; i < bitmapheadersize.length; i++) {
O.write (Bitmapheadersize[i]);
}
for (int i = 0; i < width.length; i++) {
O.write (Width[i]);
}
for (int i = 0; i < height.length; i++) {
O.write (Height[i]);
}
for (int i = 0; i < planes.length; i++) {
O.write (Planes[i]);
}
for (int i = 0; i < bitsperpixel.length; i++) {
O.write (Bitsperpixel[i]);
}
for (int i = 0; i < compression.length; i++) {
O.write (Compression[i]);
}
for (int i = 0; i < bitmapdatasize.length; i++) {
O.write (Bitmapdatasize[i]);
}
for (int i = 0; i < hresolution.length; i++) {
O.write (Hresolution[i]);
}
for (int i = 0; i < vresolution.length; i++) {
O.write (Vresolution[i]);
}
for (int i = 0; i < colors.length; i++) {
O.write (Colors[i]);
}
for (int i = 0; i < importantcolors.length; i++) {
O.write (Importantcolors[i]);
}
for (int i = 0; i < palette.length; i++) {
O.write (Palette[i]);
}
for (int i = 0; i < bitmapdata.length; i++) {
O.write (Bitmapdata[i]);
}
O.close ();
}
catch (Malformedurlexception e) {
E.printstacktrace ();
}
catch (IOException e) {
E.printstacktrace ();
}

If there is anything not clear, please contact me flcc@263.sina.com, I will do my best to help you.