Merge pull request #43 from indrasuthar07/png-support

feat: add PNG & JPEG file support for filters

Author: harshsankhla18

Makefile

@@ -1,19 +1,24 @@
 # Compiler and compiler flags
 CC = gcc
-CFLAGS = -g -std=c11 -Wall -Wextra -Werror -Wshadow
-LDFLAGS = -lm
+CFLAGS = -g -std=c11 -Wall -Wextra -Wshadow
+LDFLAGS = -lm -lpng -ljpeg
+
+# Include paths (adjust for your system)
+INCLUDES = -I/ucrt64/include
+# For Linux/macOS with standard paths, comment out INCLUDES or set to empty:
+# INCLUDES =
 
 # Source files and executable name
-SRCS = filter.c helpers.c
-TARGET = filter
+SRCS = filter.c helpers.c image_io.c bmp_io.c png_io.c jpeg_io.c
+TARGET = filter.exe
 
 # Default target
 all: $(TARGET)
 
 # Rule to link the object files into the final executable
 $(TARGET): $(SRCS)
-	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
+	$(CC) $(CFLAGS) $(INCLUDES) $^ -o $@ $(LDFLAGS)
 
 # Rule to clean up generated files
 clean:
-	rm -f $(TARGET)
+	rm -f $(TARGET) *.o

README.md

@@ -261,9 +261,81 @@ To apply a filter via command-line:
 - `B <value>`: brightness
 - `o`: oilpaint
 
-  
-Example for glow:
-filter -G input.bmp output.bmp
+#### Examples:
+
+```bash
+# Grayscale a PNG image
+./filter.exe -g input.png output.png
+# Sepia on JPEG image
+./filter.exe -s input.jpg output.jpg
+# Blur a BMP image
+./filter.exe -b input.bmp output.bmp
+# Chain multiple filters
+./filter.exe -g -b input.png output.png
+# Convert format (PNG to JPEG)
+./filter.exe -g input.png output.jpg
+# Brightness adjustment
+./filter.exe -B 40 input.jpg output.jpg
+```
+
+You can also chain multiple filters by supplying multiple tags (e.g., `./filter.exe -v -g input.bmp output.bmp` for vignette then grayscale).
+
+## Supported Image Formats
+
+The Image-Filtering tool supports multiple image formats:
+
+- **BMP**: 24-bit uncompressed BMP files
+- **PNG**: PNG images with RGB color space (supports various PNG formats including RGBA, grayscale, palette - automatically converted to RGB)
+- **JPEG**: JPEG images with RGB color space (supports grayscale and RGB JPEGs)
+
+### Format Auto-Detection
+
+The tool automatically detects the input image format based on file signatures (magic bytes). The output format is determined by the file extension of the output filename. You can convert between formats by simply changing the output file extension.
+
+### Examples with Different Formats
+
+```bash
+# Process PNG image
+./filter.exe -g photo.png photo_gray.png
+# Process JPEG image
+./filter.exe -s photo.jpg photo_sepia.jpg
+# Convert PNG to JPEG
+./filter.exe -g input.png output.jpg
+# Convert JPEG to BMP
+./filter.exe -b input.jpg output.bmp
+# Chain filters on PNG
+./filter.exe -g -b input.png output.png
+```
+
+## Building and Installation
+
+#### Windows (MSYS2)
+```bash
+# Install dependencies in MSYS2 UCRT64 terminal
+pacman -Syu
+pacman -S mingw-w64-ucrt-x86_64-gcc
+pacman -S mingw-w64-ucrt-x86_64-libpng
+pacman -S mingw-w64-ucrt-x86_64-libjpeg-turbo
+pacman -S make
+```
+
+#### Linux (Ubuntu/Debian)
+```bash
+sudo apt-get update
+sudo apt-get install libpng-dev libjpeg-dev build-essential
+```
+
+#### macOS
+```bash
+brew install libpng libjpeg
+```
+
+### Building
+
+```bash
+make clean
+make
+```
 
 You can also chain multiple filters by supplying multiple tags (e.g., `./filter vg input.bmp output.bmp` for vignette then grayscale).
 

bmp.h

@@ -14,7 +14,7 @@
 #endif
 
 // --- Bitmap File Header (14 bytes) ---
-typedef struct
+typedef struct bmp_file_header_struct
 {
     uint16_t bfType;         // File type ("BM")
     uint32_t bfSize;         // Size of the file in bytes
@@ -24,7 +24,7 @@ typedef struct
 } BITMAPFILEHEADER;
 
 // --- Bitmap Info Header (40 bytes for BITMAPINFOHEADER) ---
-typedef struct
+typedef struct bmp_info_header_struct
 {
     uint32_t biSize;            // Header size (40 bytes)
     int32_t  biWidth;           // Image width in pixels
@@ -40,7 +40,7 @@ typedef struct
 } BITMAPINFOHEADER;
 
 // --- RGB Triple (3 bytes per pixel) ---
-typedef struct
+typedef struct bmp_rgb_triple_struct
 {
     uint8_t rgbtBlue;
     uint8_t rgbtGreen;

bmp_io.c

@@ -0,0 +1,107 @@
+#include "image_io.h"
+#include "bmp.h"
+#include <stdlib.h>
+#include <string.h>
+
+// Read BMP file
+int read_bmp(const char *filename, ImageData *img) {
+    FILE *inptr = fopen(filename, "rb");
+    if (inptr == NULL) {
+        return 1;
+    }
+    BITMAPFILEHEADER bf;
+    if (fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr) != 1) {
+        fclose(inptr);
+        return 1;
+    }
+    BITMAPINFOHEADER bi;
+    if (fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr) != 1) {
+        fclose(inptr);
+        return 1;
+    }
+    if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||  bi.biBitCount != 24 || bi.biCompression != 0) {
+        fclose(inptr);
+        return 1;
+    }
+    img->height = abs(bi.biHeight);
+    img->width = bi.biWidth;
+    img->format = IMAGE_FORMAT_BMP;
+
+    img->pixels = (RGBTRIPLE **)malloc(img->height * sizeof(RGBTRIPLE *));
+    if (img->pixels == NULL) {
+        fclose(inptr);
+        return 1;
+    }
+    RGBTRIPLE *pixel_data = (RGBTRIPLE *)calloc(img->height * img->width, sizeof(RGBTRIPLE));
+    if (pixel_data == NULL) {
+        free(img->pixels);
+        fclose(inptr);
+        return 1;
+    }
+    for (int i = 0; i < img->height; i++) {
+        img->pixels[i] = pixel_data + i * img->width;
+    }
+    int padding = (4 - (img->width * sizeof(RGBTRIPLE)) % 4) % 4;
+
+    // Read pixels
+    for (int i = 0; i < img->height; i++) {
+        if (fread(img->pixels[i], sizeof(RGBTRIPLE), img->width, inptr) != (size_t)img->width) {
+            free_image(img);
+            fclose(inptr);
+            return 1;
+        }
+        fseek(inptr, padding, SEEK_CUR);
+    }
+
+    fclose(inptr);
+    return 0;
+}
+
+// Write BMP file
+int write_bmp(const char *filename, ImageData *img) {
+    FILE *outptr = fopen(filename, "wb");
+    if (outptr == NULL) {
+        return 1;
+    }
+    int padding = (4 - (img->width * sizeof(RGBTRIPLE)) % 4) % 4;
+    int row_size = img->width * sizeof(RGBTRIPLE) + padding;
+    int image_size = row_size * img->height;
+
+    BITMAPFILEHEADER bf;
+    bf.bfType = 0x4d42; 
+    bf.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + image_size;
+    bf.bfReserved1 = 0;
+    bf.bfReserved2 = 0;
+    bf.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
+
+    BITMAPINFOHEADER bi;
+    bi.biSize = sizeof(BITMAPINFOHEADER);
+    bi.biWidth = img->width;
+    bi.biHeight = img->height;
+    bi.biPlanes = 1;
+    bi.biBitCount = 24;
+    bi.biCompression = 0;
+    bi.biSizeImage = image_size;
+    bi.biXPelsPerMeter = 0;
+    bi.biYPelsPerMeter = 0;
+    bi.biClrUsed = 0;
+    bi.biClrImportant = 0;
+
+    if (fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr) != 1 || fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr) != 1) {
+        fclose(outptr);
+        return 1;
+    }
+
+    for (int i = 0; i < img->height; i++) {
+        if (fwrite(img->pixels[i], sizeof(RGBTRIPLE), img->width, outptr) != (size_t)img->width) {
+            fclose(outptr);
+            return 1;
+        }
+        for (int k = 0; k < padding; k++) {
+            fputc(0x00, outptr);
+        }
+    }
+    fclose(outptr);
+    return 0;
+}
+