How do I create an image (bmp) file?

[Mvpr]

Hi,
I have read in several images as INTEGER*2 matrices, am doing pixel manipulations with them and writing the result to an output matrix. How do I convert this output matrix into a bitmap image file?
Thanks for any help.
Mvpr

 

[DoctorDoug]

MVPR:

I have the same question on storing integer*2 matrices as bmp files.

I see the file format info described ad nauseum on the web, but wondered if you found a bit of code to do this file creation/image storage.

DoctorDoug

 

[xwb]

I know how to create a bmp file in C/C++ but I can't figure out how to do it with the compiler I have. I've got all the structures in but I can't read/write the files. There are lots of integer(len=2) and character(len=1) in the format specification. Looks like my Fortran compiler, which is the Lahey-Fujitsu elf90 (when it was free) doesn't support input/output of binary files.

Just wondering whether it is worth trying it in F77 or is everything F90/F95 based nowadays?

 

[xwb]

I've written a noddy one in F77 but it is too big to post in this forum (appx 300 lines, including comments). It will handle a 32x32 bitmap. You will have to modify the code for a bigger map. I haven't got a website and I can't be bothered to set one up. If you email me at

tech@cup.btinternet.co.uk
subject Fortran BMP

I'll email the source to you.

I don't mind if you decide to put it on your website. Just post it here to let everyone know.

 

[xwb]

Just looked at one of the other messages. Maybe 300 lines isn't so big after all. There are 2 files below. If your version of F77 does not accept includes, then you will need to replicate the header file wherever the common block is required

Header File
-----------
! BmpMap.h
!
! Bitmap file header
***********************************************************************
common /BitMap/
& bfSize,
& bfReserved,
& bfOffBits,
& biSize,
& biWidth,
& biHeight,
& biPlanes,
& biBitCount,
& biCompression,
& biSizeImage,
& biXPelsPerMeter,
& biYPelsPerMeter,
& biClrUsed,
& biClrImportant,
& bcColours,
& bcIxPerByte,
& bcBitsPerIx,
& bmpPosn,
& bfType ! Smallest so it must appear last

! type:: BmpFileHeader
character*2 bfType
integer*4 bfSize
integer*4 bfReserved ! actually Reserved1 & 2
integer*4 bfOffBits
! end type BmpFileHeader

! type:: BmpInfoHeader
integer*4 biSize
integer*4 biWidth
integer*4 biHeight
integer*2 biPlanes
integer*2 biBitCount
integer*4 biCompression
integer*4 biSizeImage
integer*4 biXPelsPerMeter
integer*4 biYPelsPerMeter
integer*4 biClrUsed
integer*4 biClrImportant
! end type BmpInfoHeader
!
! Some variables for colours
integer bcColours ! number of colours
integer bcIxPerByte ! colour indices per byte
integer bcBitsPerIx ! bits per colour index
integer bmpPosn

Source File
-----------
! WriteBmp
!
! Create a bmp file.
! This code assumes integer*2 takes up 2 bytes: not the space
! taken by 2 integers. If the implementation is such that it
! takes up the space of 2 integers, lots of declarations will
! have to be changed
!
! Many of the numbers are hard coded: no excuse except laziness
!
! Maximum image size is 32x32. If it is
! Any bigger, change all arrays preceded by !!!!!!CHANGE
!**********************************************************************
program main
! Common Blocks
! Locals
!!!!!!CHANGE
integer image(32,32)
integer imageHeight, imageWidth

call CreateImage (image, imageHeight, imageWidth)
call CreateBmp ('criss.bmp', image, imageHeight, imageWidth)
stop
end
!**********************************************************************
! Create a dummy image
!**********************************************************************
subroutine CreateImage (oImage, oHeight, oWidth)
implicit none
! Parameters
!!!!!!CHANGE
integer oImage(32,32)
integer oHeight
integer oWidth
! Common Blocks
! Locals
integer x, y

! Clear the image
oHeight = 16
oWidth = 16
do 20 x = 1, oWidth, 1
do 10 y = 1, oHeight, 1
oImage(x,y) = 0
10 continue
20 continue
! Draw a cross
do 30 x = 1, oWidth, 1
oImage(x,x) = 1
oImage(oWidth - x + 1, x) = 1
30 continue
! Put a line at the top
do 40 x = 1, oWidth, 1
oImage(x,3) = 1
40 continue
! Put a line at the side
do 50 y = 1, oHeight, 1
oImage(5,y) = 1
50 continue
return
end
!**********************************************************************
! Create a bitmap
!**********************************************************************
subroutine CreateBmp (iFilename, iImage, iWidth, iHeight)
implicit none
! Parameters
character*(*) iFilename
!!!!!!CHANGE
integer iImage(32,32)
integer iHeight
integer iWidth
! Common Blocks
! Locals
integer fhand

fhand = 10
! try
open (
& unit = fhand,
& file = iFilename,
& status = 'UNKNOWN',
& access = 'DIRECT', ! Otherwise it assumes a record header
& form = 'UNFORMATTED',
& recl = 1,
& err = 100)
goto 200
! catch
100 print *, 'Unable to open ', iFilename
return
! end catch
200 continue

call CreateBmpInfo (fhand, iWidth, iHeight)
call CreateBmpColours (fhand)
call CreateBmpData (fhand, iImage, iWidth, iHeight)
call CreateBmpFile (fhand)
return
end
!**********************************************************************
!**********************************************************************
subroutine CreateBmpFile (iHand)
implicit none
! Parameters
integer iHand
! Common Blocks
include 'BitMap.h'
! Locals

bfType = 'BM'
! bfSize is set by CreateBmpData
bfReserved = 0
bfOffBits = 62
write (iHand, rec=1) bfType, bfSize, bfReserved, bfOffBits
return
end
!**********************************************************************
! Write Bmp Info Header to the file
!**********************************************************************
subroutine CreateBmpInfo (iHand, iWidth, iHeight)
implicit none
! Parameters
integer iHand
integer iWidth
integer iHeight
! Common Blocks
include 'BitMap.h'
! Locals
integer scanwidth

biSize = 40 ! Size of BITMAPINFOHEADER
biWidth = iWidth
biHeight = iHeight
biPlanes = 1 ! for a 2 colour bitmap
biBitCount = 1 ! for a 2 colour bitmap
biCompression = 0 ! no compression
! Minimum number of bytes
scanwidth = ((biWidth - 1) / 8 + 1)
! Scan width must be a multiple of 4
scanwidth = ((scanwidth - 1) / 4 + 1) * 4
biSizeImage = scanwidth * iHeight
biXPelsPerMeter = 3780 ! Some random figure that MS chooses
biYPelsPerMeter = 3780
biClrUsed = 0 ! for a 2 colour bitmap
biClrImportant = 0 ! for a 2 colour bitmap
bmpPosn = 55 ! where the colour table starts
write (iHand, rec = 15)
& biSize,
& biWidth,
& biHeight,
& biPlanes,
& biBitCount,
& biCompression,
& biSizeImage,
& biXPelsPerMeter,
& biYPelsPerMeter,
& biClrUsed,
& biClrImportant
return
end
!**********************************************************************
! Write the data to the file. This is written backwards because
! .bmp format stores everything backwards
!**********************************************************************
subroutine CreateBmpData (iHand, iImage, iHeight, iWidth)
implicit none
! Parameters
integer iHand
!!!!!!CHANGE
integer iImage(32,32)
integer iHeight
integer iWidth
! Common Blocks
include 'BitMap.h'
! Locals
integer row, col
!!!!!!CHANGE At least iImage xmax / 32
character bmp(32)*1
integer ix, ixmax, posninc, patn

ixmax = ((biWidth - 1) / 8 + 1)
! Get the nearest number of 32-bit words
ixmax = ((ixmax - 1) / 4 + 1) * 4

do 30 row = iHeight, 1, -1
do 10 ix = 1, ixmax, 1
bmp(ix) = char (0)
10 continue
ix = 1
patn = 0
do 20 col = 1, iWidth, 1
patn = iShft (patn, 1)
! 0 = black, 1 = white
if (iImage(col,row) .eq. 0)
& patn = iOr (patn, 1)

if (mod (col, 8) .eq. 0) then
bmp(ix) = char (patn)
patn = 0
ix = ix + 1
endif
20 continue
write (iHand, rec = bmpPosn) (bmp(ix), ix = 1, ixmax, 1)
bmpPosn = bmpPosn + ixmax
30 continue
bfSize = bmpPosn - 1
return
end
!**********************************************************************
! Set the colours
!**********************************************************************
subroutine CreateBmpColours (iHand)
implicit none
! Parameters
integer iHand
! Common Blocks
include 'BitMap.h'
! Locals
character*1 red, green, blue, reserved

! bmpPosn is initialized in CreateBmpInfo
! Set up for B/W bitmap
bcColours = 2
bcIxPerByte = 8
bcBitsPerIx = 1
! Black
red = char(0)
green = char(0)
blue = char(0)
reserved = char(0)
write (iHand, rec = bmpPosn) blue, green, red, reserved
bmpPosn = bmpPosn + 4
! White
red = char(255)
green = char(255)
blue = char(255)
write (iHand, rec = bmpPosn) blue, green, red, reserved
bmpPosn = bmpPosn + 4
return
end

 

[xwb]

Sources are also available under code samples on

http://www.forceproject.hpg.ig.com.br/