Here is the check50 output:
:) edges correctly filters middle pixel
:( edges correctly filters pixel on edge expected "213 228 255\n", not "213 228 140\n"
:( edges correctly filters pixel in corner expected "76 117 255\n", not "76 117 66\n"
:( edges correctly filters 3x3 image expected "76 117 255\n21...", not "76 117 66\n213..."
:( edges correctly filters 4x4 image expected "76 117 255\n21...", not "76 117 66
Helpers.c (My problem is here, the rest of the code was provided by cs50, I include to to make a minimal reproducible example, and just in case you want to check any of the structs)
void edges(int height, int width, RGBTRIPLE image[height][width])
{
int sobel[3][3] =
{
{-1, 0, 1},
{-2, 0, 2},
{-1, 0, 1}
};
RGBTRIPLE edged[height][width];
for (int i = 0; i<height; i++){
for (int j = 0; j<width; j++){
double GxRed = 0 , GxGreen = 0 , GxBlue = 0 , GyRed = 0 , GyGreen = 0 , GyBlue = 0;
int boxRow[3][3] = {{i-1, i-1, i-1}, {i, i, i}, {i+1, i+1, i+1}}, boxCol[3][3] = {{j-1, j, j+1}, {j-1, j, j+1}, {j-1, j, j+1}};
for (int x = 0; x<3; x++){
for (int y = 0; y<3; y++){
if (boxRow[x][y] >= 0 && boxRow[x][y] < height && boxCol[x][y] >= 0 && boxCol[x][y] < width){
GxRed += image[boxRow[x][y]][boxCol[x][y]].rgbtRed * sobel[x][y];
GxGreen += image[boxRow[x][y]][boxCol[x][y]].rgbtGreen * sobel[x][y];
GxBlue += image[boxRow[x][y]][boxCol[x][y]].rgbtBlue * sobel[x][y];
GyRed += image[boxRow[x][y]][boxCol[x][y]].rgbtRed * sobel[y][x];
GyGreen += image[boxRow[x][y]][boxCol[x][y]].rgbtGreen * sobel[y][x];
GyBlue += image[boxRow[x][y]][boxCol[x][y]].rgbtBlue * sobel[y][x];
}
}
}
edged[i][j].rgbtRed = round(sqrt(pow(GxRed, 2) + pow(GyRed, 2)));
if (edged[i][j].rgbtRed > 255) {edged[i][j].rgbtRed = 255;}
if (edged[i][j].rgbtRed < 0) {edged[i][j].rgbtRed = 0;}
edged[i][j].rgbtGreen = round(sqrt(pow(GxGreen, 2) + pow(GyGreen, 2)));
if (edged[i][j].rgbtGreen > 255) {edged[i][j].rgbtGreen = 255;}
if (edged[i][j].rgbtGreen < 0) {edged[i][j].rgbtGreen = 0;}
edged[i][j].rgbtBlue = round(sqrt(pow(GxBlue, 2) + pow(GyBlue, 2)));
if (edged[i][j].rgbtBlue > 255) {edged[i][j].rgbtBlue = 255;}
if (edged[i][j].rgbtBlue < 0) {edged[i][j].rgbtBlue = 0;}
}
}
for (int i = 0; i<height; i++){
for (int j = 0; j<width; j++){
image[i][j] = edged[i][j];
}
}
return;
}
This is helpers.h
// Convert image to grayscale
void grayscale(int height, int width, RGBTRIPLE image[height][width]);
// Reflect image horizontally
void reflect(int height, int width, RGBTRIPLE image[height][width]);
// Detect edges
void edges(int height, int width, RGBTRIPLE image[height][width]);
// Blur image
void blur(int height, int width, RGBTRIPLE image[height][width]);
This is bmp.h
#include <stdint.h>
/**
* Common Data Types
*
* The data types in this section are essentially aliases for C/C++
* primitive data types.
*
* Adapted from http://msdn.microsoft.com/en-us/library/cc230309.aspx.
* See http://en.wikipedia.org/wiki/Stdint.h for more on stdint.h.
*/
typedef uint8_t BYTE;
typedef uint32_t DWORD;
typedef int32_t LONG;
typedef uint16_t WORD;
/**
* BITMAPFILEHEADER
*
* The BITMAPFILEHEADER structure contains information about the type, size,
* and layout of a file that contains a DIB [device-independent bitmap].
*
* Adapted from http://msdn.microsoft.com/en-us/library/dd183374(VS.85).aspx.
*/
typedef struct
{
WORD bfType;
DWORD bfSize;
WORD bfReserved1;
WORD bfReserved2;
DWORD bfOffBits;
} __attribute__((__packed__))
BITMAPFILEHEADER;
/**
* BITMAPINFOHEADER
*
* The BITMAPINFOHEADER structure contains information about the
* dimensions and color format of a DIB [device-independent bitmap].
*
* Adapted from http://msdn.microsoft.com/en-us/library/dd183376(VS.85).aspx.
*/
typedef struct
{
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount;
DWORD biCompression;
DWORD biSizeImage;
LONG biXPelsPerMeter;
LONG biYPelsPerMeter;
DWORD biClrUsed;
DWORD biClrImportant;
} __attribute__((__packed__))
BITMAPINFOHEADER;
/**
* RGBTRIPLE
*
* This structure describes a color consisting of relative intensities of
* red, green, and blue.
*
* Adapted from http://msdn.microsoft.com/en-us/library/aa922590.aspx.
*/
typedef struct
{
BYTE rgbtBlue;
BYTE rgbtGreen;
BYTE rgbtRed;
} __attribute__((__packed__))
RGBTRIPLE;
This is filter.c
#include <stdio.h>
#include <stdlib.h>
#include "helpers.h"
int main(int argc, char *argv[])
{
// Define allowable filters
char *filters = "begr";
// Get filter flag and check validity
char filter = getopt(argc, argv, filters);
if (filter == '?')
{
printf("Invalid filter.\n");
return 1;
}
// Ensure only one filter
if (getopt(argc, argv, filters) != -1)
{
printf("Only one filter allowed.\n");
return 2;
}
// Ensure proper usage
if (argc != optind + 2)
{
printf("Usage: ./filter [flag] infile outfile\n");
return 3;
}
// Remember filenames
char *infile = argv[optind];
char *outfile = argv[optind + 1];
// Open input file
FILE *inptr = fopen(infile, "r");
if (inptr == NULL)
{
printf("Could not open %s.\n", infile);
return 4;
}
// Open output file
FILE *outptr = fopen(outfile, "w");
if (outptr == NULL)
{
fclose(inptr);
printf("Could not create %s.\n", outfile);
return 5;
}
// Read infile's BITMAPFILEHEADER
BITMAPFILEHEADER bf;
fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
// Read infile's BITMAPINFOHEADER
BITMAPINFOHEADER bi;
fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
// Ensure infile is (likely) a 24-bit uncompressed BMP 4.0
if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
bi.biBitCount != 24 || bi.biCompression != 0)
{
fclose(outptr);
fclose(inptr);
printf("Unsupported file format.\n");
return 6;
}
// Get image's dimensions
int height = abs(bi.biHeight);
int width = bi.biWidth;
// Allocate memory for image
RGBTRIPLE(*image)[width] = calloc(height, width * sizeof(RGBTRIPLE));
if (image == NULL)
{
printf("Not enough memory to store image.\n");
fclose(outptr);
fclose(inptr);
return 7;
}
// Determine padding for scanlines
int padding = (4 - (width * sizeof(RGBTRIPLE)) % 4) % 4;
// Iterate over infile's scanlines
for (int i = 0; i < height; i++)
{
// Read row into pixel array
fread(image[i], sizeof(RGBTRIPLE), width, inptr);
// Skip over padding
fseek(inptr, padding, SEEK_CUR);
}
// Filter image
switch (filter)
{
// Blur
case 'b':
blur(height, width, image);
break;
// Edges
case 'e':
edges(height, width, image);
break;
// Grayscale
case 'g':
grayscale(height, width, image);
break;
// Reflect
case 'r':
reflect(height, width, image);
break;
}
// Write outfile's BITMAPFILEHEADER
fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);
// Write outfile's BITMAPINFOHEADER
fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);
// Write new pixels to outfile
for (int i = 0; i < height; i++)
{
// Write row to outfile
fwrite(image[i], sizeof(RGBTRIPLE), width, outptr);
// Write padding at end of row
for (int k = 0; k < padding; k++)
{
fputc(0x00, outptr);
}
}
// Free memory for image
free(image);
// Close files
fclose(inptr);
fclose(outptr);
return 0;
}
This is Makefile
filter:
clang -ggdb3 -gdwarf-4 -O0 -Qunused-arguments -std=c11 -Wall -Werror -Wextra -Wno-gnu-folding-constant -Wno-sign-compare -Wno-unused-parameter -Wno-unused-variable -Wshadow -lm -o filter filter.c helpers.c
To reproduce use any .bmp image. when you run the program, the command line arguments are -e INFILE.bmp OUTFILE.bmp
My code seems to be having problems with the blue values(I think...). I've checked other posts, where they had a typo, I've checked and there doesn't seem to be any. Others used rgbtriple so the values would sum until 255 and stop, but here I am using doubles. I hope its not something stupid, but I've been checking and can't find the problem. Hope someone can help me. Thank you https://cs50.harvard.edu/x/2022/psets/4/filter/more/. (Here is the link to a description of the problem, you can skip to the edges part.)
