Added BMP header reader in D language

1 files changed, 111 insertions, 0 deletions

diff --git a/d-bmp-header/main.d b/d-bmp-header/main.d
new file mode 100644
index 0000000..c8fcaf0
--- /dev/null
+++ b/d-bmp-header/main.d
@@ -0,0 +1,111 @@
+import std.stdio;
+import std.file;
+import std.format;
+import std.string;
+import std.range;
+import std.algorithm;
+import std.array;
+import std.math;
+
+// BMP file header (14 bytes).
+struct BitmapFileHeader {
+        char[2] signature;      // "BM" signature
+        uint fileSize;          // Size of the file in bytes
+        ushort reserved1;       // Reserved (0)
+        ushort reserved2;       // Reserved (0)
+        uint dataOffset;        // Offset to the start of image data
+}
+
+// BMP info header (40 bytes for BITMAPINFOHEADER).
+struct BitmapInfoHeader {
+        uint size;              // Size of this header (40 bytes)
+        int width;              // Image width in pixels
+        int height;             // Image height in pixels
+        ushort planes;          // Number of color planes (must be 1)
+        ushort bitsPerPixel;    // Bits per pixel (1, 4, 8, 16, 24, or 32)
+        uint compression;       // Compression method (0 = none, 1 = RLE-8, 2 = RLE-4)
+        uint imageSize;         // Size of the image data in bytes
+        int xPixelsPerMeter;    // Horizontal resolution (pixels per meter)
+        int yPixelsPerMeter;    // Vertical resolution (pixels per meter)
+        uint colorsUsed;        // Number of colors in the palette
+        uint importantColors;   // Number of important colors used (0 = all)
+}
+
+// RGB pixel structure.
+struct RGB {
+        ubyte blue;
+        ubyte green;
+        ubyte red;
+
+        string toString() const {
+                return format("RGB(%d, %d, %d)", red, green, blue);
+        }
+}
+
+void main(string[] args) {
+        if (args.length < 2) {
+                writeln("Usage: main <filename.bmp>");
+                return;
+        }
+
+        string fileName = args[1];
+
+        try {
+                // Read the file.
+                auto file = File(fileName, "rb");
+
+                // Read the BMP file header.
+                BitmapFileHeader fileHeader;
+                file.rawRead((&fileHeader)[0..1]);
+
+                // Check if it's a valid BMP file
+                if (fileHeader.signature != "BM") {
+                        writeln("Error: Not a valid BMP file");
+                        return;
+                }
+
+                // Read the BMP info header.
+                BitmapInfoHeader infoHeader;
+                file.rawRead((&infoHeader)[0..1]);
+
+                // Display header information.
+                writeln("BMP File Header Information:");
+                writefln("  Signature: %s", fileHeader.signature);
+                writefln("  File Size: %d bytes", fileHeader.fileSize);
+                writefln("  Data Offset: %d bytes", fileHeader.dataOffset);
+
+                writeln("\nBMP Info Header Information:");
+                writefln("  Header Size: %d bytes", infoHeader.size);
+                writefln("  Image Width: %d pixels", infoHeader.width);
+                writefln("  Image Height: %d pixels", infoHeader.height);
+                writefln("  Color Planes: %d", infoHeader.planes);
+                writefln("  Bits Per Pixel: %d", infoHeader.bitsPerPixel);
+
+                // Display compression method.
+                string compressionMethod;
+                switch (infoHeader.compression) {
+                        case 0: compressionMethod = "None (BI_RGB)"; break;
+                        case 1: compressionMethod = "RLE-8 (BI_RLE8)"; break;
+                        case 2: compressionMethod = "RLE-4 (BI_RLE4)"; break;
+                        case 3: compressionMethod = "Bitfields (BI_BITFIELDS)"; break;
+                        default: compressionMethod = format("Unknown (%d)", infoHeader.compression);
+                }
+                writefln("  Compression: %s", compressionMethod);
+
+                writefln("  Image Size: %d bytes", infoHeader.imageSize);
+                writefln("  Horizontal Resolution: %d pixels/meter", infoHeader.xPixelsPerMeter);
+                writefln("  Vertical Resolution: %d pixels/meter", infoHeader.yPixelsPerMeter);
+                writefln("  Colors Used: %d", infoHeader.colorsUsed);
+                writefln("  Important Colors: %d", infoHeader.importantColors);
+
+                // Calculate color depth information.
+                int numColors = (infoHeader.bitsPerPixel <= 8) ? (1 << infoHeader.bitsPerPixel) : 0;
+                if (numColors > 0) {
+                        writefln("  Color Palette: %d colors", numColors);
+                } else {
+                        writefln("  Color Palette: None (direct color)");
+                }
+        } catch (Exception e) {
+                writefln("Error reading BMP file: %s", e.msg);
+        }
+}