In this assignment, you are asked to manipulate image from a 24-bit uncompressed bmp file. (The
format of bmp files is given in http://en.wikipedia.org/wiki/BMP_file_format).
To help with reading and
writing the image file, you are given library functions and an example that deal with the bmp file (in a
zip file on my faculty website). In the example, the image is flipped horizontally.
You are asked
to implement the verticalflip(), enlarge() and rotate() functions: the first flips the image vertically, the
second is used to enlarge the image by an integer scale factor; the last one is used to rotate the
image either clockwise or counter-clockwise by a certain degree (which must be a multiple of 90)
depending whether the rotation degree is positive or negative. Positive is clockwise and negative is
The program should take the follow command-line options:
%./bmptool [-s scale | -r degree | -f | -v ] [-o output_file] [input_file]
Where -s means to scale the image by the given ‘scale’ (a positive integer: 1, 2, 3, …), -r means to
rotate the image by ‘degree’ (which must be a multiple of 90, clockwise if positive, counter-clockwise
if negative), -v means to flip the image vertically and -f means to flip the image horizontally.
assume for each type (-s, -r, -f, or -v), the command line has at most one option. That is, the user is
not supposed to do something like “./bmptool -s 2 -s 4”. If that happens, you can either prompt with
an error, or take either 2 or 4 as the scale. However, the user may present a combination, say,
‘./bmptool -r 90 -s 4’. If multiple option types are present, the order for processing the image is that
you do scale first, then rotate, and then flip vertically and finally flip horizontally.
You are required to use getopt() to process the command-line. If ‘-o output_file’ is missing, use
standard output. If ‘input_file’ is missing, use standard input. The options to use standard input or
standard output will only be used when chaining commands.
Make sure the program returns 0 on success. In that case, one can ‘chain’ the commands using pipes, like:
% bmptool -s 4 1.bmp | bmptool -r -90 | bmptool -f -o 2.bmp
Your program needs to provide necessary sanity-check for command line arguments and handle
various error conditions and prompt the user with helpful information. You need to use getopt() to
process the command line arguments.
Test your program with various combinations to make sure it
works as expected. You must use dynamic memory to store the content of the new image before
writing out to file. You need to reclaim memory afterwards to prevent from memory leaks.
Please submit your work through Canvas as one zip file called FirstnameLastnameA2.zip. Follow the
instructions below carefully (to avoid unnecessary loss of grade). Include your source code, your
Makefile, the bmplib files that I have provided, and the example.bmp file in the zip file.
I should be
able to create the excecutable by typing ‘make’. The Makefile should also contain a ‘clean’ target for
cleaning up the directory (removing all temporary files and object files). Make sure you don’t include
intermediate files: *.o, executables, *~, etc., in your submission. (There’ll be a penalty for including
unnecessary intermediate files).
Please make sure you submit homework before the deadline. There will be a late penalty as per the
If the program does not compile and do something useful when it runs it will not earn any credit.