Program 2: Grayscale Converter

Summary and Goal

Instructions

• Write a program in C to read a PPM file from standard in and output put it in grayscale using PGM format to standard out.
• The color-to-grayscale conversion to be used is
  luminance = red * .3 + green * .59 + blue * .11 . Make sure to round.
• To test your program, redirect a PPM file to standard in, and redirect to output to a file. e.g. grayscale < in.ppm > out.pgm
• If you wish to reduce the file size without losing information, use IrfanView to convert your ppm file to png.
• View the output with an image viewer.
• You may use 101asg2in1.png and 101asg2in2.png to test your program. Be sure to convert these files to PPM format before you use them.
• You may use 101asg2out1.png and 101asg2out2.png to compare with your results.
• You can convert png to ppm format with IrfanView

Style

• Use either 3 or 4 spaces for each indentation. Be consistent. Pick a number and stay with it.
• Do not use tabs to indent because the printer does not have the same tab spacing as the computer. Use the space bar to indent.
• Put every C statement a separate line.
• (Optional) If the condition for execution, such as in a while or if statement can be written in the form "( constant == var )" it may not be written in the form "( var == constant )".
• Comments must be included when they will aid the reader in understanding the program. Do not comment the obvious. Comment what you are doing, not how.
• Use meaningful variable names. Long names are better than unclear names.
• Do not use the single letter 'o' or the single letter 'l' for variable names.
• Use white space to set off logical ideas. Comment logical blocks.

Assignment Credit

• Turn this assignment in a full 24 hours early (to the minute) to receive an extra 5 points.
• Do some other interesting transformation to the image and output it at PPM format. Examples are fading the image, color balancing, duotoning to a color other than gray, and changing the colors to be more cartoony.
• For this assignment, there will be no "first in" extra credit. Instead, The best extra credit image effect will be awarded an extra 5 points. (second receives 4 points, etc.)

Submission Instructions

• Your C program file should be named grayscale.c .
• Hand in grayscale.c no later than 11:59 p.m. Friday, October 17^th .
• Email grayscale.c as an attachment to your lab professor. Paste into the subject line CSC 112 Program 2 grayscale.c

  1. source code attachment

  2. subject line: CSC 112 Program 2 grayscale.c

• Keep the email submission confirmation for reference later.