Question

Design and implement a C version of the color match program. As a starting point, use the file
HW2-1-shell.c. The program should employ a reasonable algorithm that compares all
pairings of colors in the palette exactly once. A color should not be compared to itself. Nor should
two colors be compared to each other more than once. Your C program should print out the total
component color difference for the closest pair using the print string provided in the shell code.
Name the file HW2-1.C and upload it to Canvas by the scheduled due date.
The shell program HW2-1-shell.c includes a reader function Load_Mem() that loads the
values from a text file. You should use gcc under Ubuntu to develop your program. Sample test
files (test119.txt, test30.txt, test111.txt) are provided – the number in the
name of each file indicates the correct answer for the min component difference. You should
compile and run your program using the Linux command lines:
> gcc HW2-1.c –g –Wall –o HW2-1
> ./HW2-1 test119.txt
You can create additional test files using MiSaSiM to run HW2-2-shell.asm, go to the end
of the trace, and use the “Dump” memory menu button to save the memory to a text file with the
correct answer (the value in $13) in the name of the file.

2. Design and implement a MIPS version of the color match program. A description of the MIPS
library routines you need is given below. Use the file HW2-2-shell.asm as a starting point.
The results should be returned by your program in $10 (minimum total component difference),
$11 (memory address of closest color A), and $12 (memory address of closest color B). You must
use these register conventions or the automated grader will score your program incorrectly.
Memory should only be used for input to your program. Your program must return to the
operating system via the jr instruction. Programs that include infinite loops or produce
simulator warnings or errors will receive zero credit. Name the file HW2-2.asm and upload it to
Canvas by the scheduled due date.

HW2-1-shell.c.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

/* Color Matcher

This program finds the two closest colors in an array of packed RGB values,
based on the total component difference (computed as a sum of absolute
difference.) It prints the total component difference of the two closest colors.

Date:
Your Name:
*/

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
/* you may change and add to these declarations and initializations */
unsigned   Pixels[8];
int   NumPixels, MinDelta=-55; // temporary initial value
int Load_Mem(char *, unsigned *);

if (argc != 2) {
printf("usage: ./HW2-1 valuefile ");
exit(1);
}
NumPixels = Load_Mem(argv[1], Pixels);
if (NumPixels != 8) {
printf("valuefiles must contain 8 entries ");
exit(1);
}

/* Your code goes here */
  
printf("The two closest colors have a total component difference of %d ", MinDelta);
exit(0);
}

/* This routine loads in up to 8 newline delimited unsigned integers from
a named file in the local directory. The values are placed in the
passed unsigned integer array. The number of input integers is returned. */

int Load_Mem(char *InputFileName, unsigned PixelArray[]) {
int   N, Addr, NumVals;
unsigned Value;
FILE   *FP;
  
FP = fopen(InputFileName, "r");
if (FP == NULL) {
printf("%s could not be opened; check the filename ", InputFileName);
return 0;
} else {
for (N=0; N < 8; N++) {
NumVals = fscanf(FP, "%d: %d", &Addr, &Value);
if (NumVals == 2)
   PixelArray[N] = Value;
else
   break;
}
fclose(FP);
return N;
}
}

--------------------------------------------------------------------------------------------------------------------------

HW2-2-shell.asm

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

# Color Matcher
#
# Your Name:
#
# Date:
#
# This program finds the two closest colors in a eight color palette.
#
# required output register usage:
# $10: minimum total component difference
# $11 and $12: memory addresses of the two closest colors

.data
Array: .alloc 8 # allocate static space for packed color data

.text
ColorMatch: addi $1, $0, Array # set memory base
swi 500 # create color palette and update memory

######################################################
# Temporary: the following 3 instructions demo use of swi 581.
# Be sure to replace them.
addi $10, $0, 48 # guess min component difference
addi $11, $1, 12 # guess an address
addi $12, $1, 4 # guess an address
######################################################

swi 581 # report answer (in $10, $11, $12)
jr $31 # return to caller

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------email to [email protected] if possible

Answer 1

The algorithm is simply:

1.Select first color from palette

2.Select second color from palette, from remaining colors

(we start from the rest of the colors so that we don't count the same pair twice i.e. [i,j] and [j,i])

3.calculate absolute value difference of the 2 colors

4.if the current difference is less than the minimum value, update the minimum value with the current difference

Below is the complete code:

#include <stdio.h>

#include <stdlib.h>

int main(int argc, char *argv[]) {

unsigned Pixels[8];

int NumPixels, MinDelta=-55; // temporary initial value

int Load_Mem(char *, unsigned *);

if (argc != 2) {

printf("usage: ./HW2-1 valuefile ");

exit(1);

}

NumPixels = Load_Mem(argv[1], Pixels);

if (NumPixels != 8) {

printf("valuefiles must contain 8 entries ");

exit(1);

}

int i,j,n=NumPixels;

MinDelta=99999;

for(i=0;i<n;i++)

{

for(j=i+1;j<n;j++)

{

int color_diff=(Pixels[i]-Pixels[j]);

if(color_diff<0)

color_diff=0-color_diff;

if(color_diff<MinDelta)

MinDelta=color_diff;

}

}

printf("The two closest colors have a total component difference of %d ", MinDelta);

exit(0);

}

int Load_Mem(char *InputFileName, unsigned PixelArray[]) {

int N, Addr, NumVals;

unsigned Value;

FILE *FP;

FP = fopen(InputFileName, "r");

if (FP == NULL) {

printf("%s could not be opened; check the filename ", InputFileName);

return 0;

} else {

for (N=0; N < 8; N++) {

NumVals = fscanf(FP, "%d: %d", &Addr, &Value);

if (NumVals == 2)

PixelArray[N] = Value;

else

break;

}

fclose(FP);

return N;

}

}