Merge pull request mike42#43 from mike42/feature/35-bmp

Add BMP file reader
parallels999 · Jul 8, 2019 · 4847807 · 4847807
2 parents 417526b + ab3cf1a
commit 4847807
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diff --git a/README.md b/README.md
@@ -63,6 +63,7 @@ As a small project, we can't do everything. In particular, `gfx-php` is not like
 
 This repository uses test files from other projects:
 
+- [BMP Suite](http://entropymine.com/jason/bmpsuite/) by Jason Summers.
 - [PyGIF](https://github.com/robert-ancell/pygif) test suite by Robert Ancell.
 - [pngsuite](http://www.schaik.com/pngsuite/) by Willem van Schaik.
 

diff --git a/docs/user/formats.rst b/docs/user/formats.rst
@@ -50,6 +50,14 @@ The GIF codec is used where the input has the ``gif`` file extension. Any well-f
 
 A GIF image will always be loaded into an instance of :class:`IndexedRasterImage`, which makes palette information available.
 
+PNG
+^^^
+
+The BMP codec is used where the input has the ``bmp`` or ``dib`` file extensions.
+
+Only uncompressed 24-bit color bitmap images may currently be read. The returned object will be an
+instance of instance of :class:`RgbRasterImage`.
+
 Netpbm Formats
 ^^^^^^^^^^^^^^
 

diff --git a/src/Mike42/GfxPhp/Codec/Bmp/BmpFile.php b/src/Mike42/GfxPhp/Codec/Bmp/BmpFile.php
@@ -0,0 +1,106 @@
+<?php
+namespace Mike42\GfxPhp\Codec\Bmp;
+
+use Exception;
+use Mike42\GfxPhp\Codec\Common\DataInputStream;
+use Mike42\GfxPhp\RasterImage;
+use Mike42\GfxPhp\RgbRasterImage;
+
+class BmpFile
+{
+    const BMP_SIGNATURE = "BM";
+
+    private $fileHeader;
+    private $infoHeader;
+    private $uncompressedData;
+
+    public function __construct(BmpFileHeader $fileHeader, BmpInfoHeader $infoHeader, array $data)
+    {
+        $this -> fileHeader = $fileHeader;
+        $this -> infoHeader = $infoHeader;
+        $this -> uncompressedData = $data;
+    }
+
+    public static function fromBinary(DataInputStream $data) : BmpFile
+    {
+        // Read two different headers
+        $fileHeader = BmpFileHeader::fromBinary($data);
+        $infoHeader = BmpInfoHeader::fromBinary($data);
+        if ($infoHeader -> bpp != 0 &&
+            $infoHeader -> bpp != 1 &&
+            $infoHeader -> bpp != 4 &&
+            $infoHeader -> bpp != 8 &&
+            $infoHeader -> bpp != 16 &&
+            $infoHeader -> bpp != 24 &&
+            $infoHeader -> bpp != 32) {
+            throw new Exception("Bit depth " . $infoHeader -> bpp . " not valid.");
+        } else if ($infoHeader -> bpp != 24) {
+            // Fail early to give a clearer error for the things which aren't tested yet
+            throw new Exception("Bit depth " . $infoHeader -> bpp . " not implemented.");
+        }
+        // Skip color table (allowed in a true color image, but not useful)
+        if ($infoHeader -> colors > 0) {
+            // for non-truecolor images, 0 will mean 2^bpp.
+            // Size of each entry may also be variable
+            $data -> read($infoHeader -> colors * 4);
+        }
+        // Determine compressed & uncompressed size
+        $rowSizeBytes = intdiv(($infoHeader -> bpp * $infoHeader -> width + 31), 32) * 4;
+        $uncompressedImgSizeBytes = $rowSizeBytes * $infoHeader -> height;
+        if ($infoHeader -> compression == BmpInfoHeader::B1_RGB) {
+            $compressedImgSizeBytes = $uncompressedImgSizeBytes;
+        } else {
+            $compressedImgSizeBytes = $infoHeader -> compressedSize;
+        }
+        $compressedImgData = $data -> read($compressedImgSizeBytes);
+        // De-compress if necessary
+        switch ($infoHeader -> compression) {
+            case BmpInfoHeader::B1_RGB:
+                $uncompressedImgData = $compressedImgData;
+                break;
+            case BmpInfoHeader::B1_RLE8:
+            case BmpInfoHeader::B1_RLE4:
+            case BmpInfoHeader::B1_BITFILEDS:
+            case BmpInfoHeader::B1_JPEG:
+            case BmpInfoHeader::B1_PNG:
+            case BmpInfoHeader::B1_ALPHABITFIELDS:
+            case BmpInfoHeader::B1_CMYK:
+            case BmpInfoHeader::B1_CMYKRLE8:
+            case BmpInfoHeader::B1_CMYKRLE4:
+                throw new Exception("Compression method not implemented");
+            default:
+                throw new Exception("Bad compression method");
+        }
+        // Account for padding, row order
+        $paddedLines = str_split($uncompressedImgData, $rowSizeBytes);
+        $dataLines = [];
+        $rowDataBytes = intdiv($infoHeader -> bpp * $infoHeader -> width + 7, 8); // Excludes padding bytes
+        for ($i = count($paddedLines) - 1; $i >= 0; $i--) { // Iterate lines backwards
+            $dataLines[] = substr($paddedLines[$i], 0, $rowDataBytes);
+        }
+        $uncompressedImgData = implode("", $dataLines);
+        // Account for RGB vs BGR in file format
+        if ($infoHeader -> bpp == 24) {
+            $pixels = str_split($uncompressedImgData, 3);
+            array_walk($pixels, ["\\Mike42\\GfxPhp\\Codec\\Bmp\\BmpFile", "transformRevString"]);
+            $uncompressedImgData = implode("", $pixels);
+        }
+        // Convert to array of numbers 0-255.
+        $dataArray = array_values(unpack("c*", $uncompressedImgData));
+        return new BmpFile($fileHeader, $infoHeader, $dataArray);
+    }
+
+    public function toRasterImage() : RasterImage
+    {
+        if ($this -> infoHeader -> bpp == 24) {
+            return RgbRasterImage::create($this -> infoHeader -> width, $this -> infoHeader -> height, $this -> uncompressedData);
+        }
+        throw new Exception("Unknown bit depth " . $this -> infoHeader -> bpp);
+    }
+
+    public static function transformRevString(&$item, $key)
+    {
+        // Convert RGB to BGR
+        $item = strrev($item);
+    }
+}
diff --git a/src/Mike42/GfxPhp/Codec/Bmp/BmpFileHeader.php b/src/Mike42/GfxPhp/Codec/Bmp/BmpFileHeader.php
@@ -0,0 +1,31 @@
+<?php
+
+
+namespace Mike42\GfxPhp\Codec\Bmp;
+
+use Exception;
+use Mike42\GfxPhp\Codec\Common\DataInputStream;
+
+class BmpFileHeader
+{
+    public $offset;
+    public $size;
+
+    public function __construct(string $fileType, int $size, int $offset)
+    {
+        $this -> fileType = $fileType;
+        $this -> size = $size;
+        $this -> offset = $offset;
+    }
+
+    public static function fromBinary(DataInputStream $data) : BmpFileHeader
+    {
+        $fileType = $data->read(2);
+        if (array_search($fileType, ["BM", "BA", "CI", "CP", "IC", "PT", "OS"]) === false) {
+            throw new Exception("Not a bitmap image");
+        }
+        $fileHeaderData = $data->read(12);
+        $fields = unpack("Vsize/vreserved1/vreserved2/Voffset", $fileHeaderData);
+        return new BmpFileHeader($fileType, $fields['size'], $fields['offset']);
+    }
+}
diff --git a/src/Mike42/GfxPhp/Codec/Bmp/BmpInfoHeader.php b/src/Mike42/GfxPhp/Codec/Bmp/BmpInfoHeader.php
@@ -0,0 +1,90 @@
+<?php
+namespace Mike42\GfxPhp\Codec\Bmp;
+
+use Exception;
+use Mike42\GfxPhp\Codec\Common\DataInputStream;
+
+class BmpInfoHeader
+{
+    const BITMAPCOREHEADER_SIZE = 12;
+    const OS21XBITMAPHEADER_SIZE = 12;
+    const BITMAPINFOHEADER_SIZE = 40;
+
+    const B1_RGB = 0;
+    const B1_RLE8 = 1;
+    const B1_RLE4 = 2;
+    const B1_BITFILEDS = 3;
+    const B1_JPEG = 4;
+    const B1_PNG = 5;
+    const B1_ALPHABITFIELDS = 6;
+    const B1_CMYK = 11;
+    const B1_CMYKRLE8 = 12;
+    const B1_CMYKRLE4 = 13;
+
+    public $bpp;
+    public $colors;
+    public $compressedSize;
+    public $compression;
+    public $headerSize;
+    public $height;
+    public $hprizontalRes;
+    public $importantColors;
+    public $planes;
+    public $verticalRes;
+    public $width;
+
+    public function __construct(int $headerSize, int $width, int $height, int $planes, int $bpp, int $compression = 0, int $compressedSize = 0, int $horizontalRes = 0, int $verticalRes = 0, int $colors = 0, int $importantColors = 0)
+    {
+        $this -> headerSize = $headerSize;
+        $this -> width = $width;
+        $this -> height = $height;
+        $this -> planes = $planes;
+        $this -> bpp = $bpp;
+        $this -> compression = $compression;
+        $this -> compressedSize = $compressedSize;
+        $this -> hprizontalRes = $horizontalRes;
+        $this -> verticalRes = $verticalRes;
+        $this -> colors = $colors;
+        $this -> importantColors = $importantColors;
+    }
+
+    public static function fromBinary(DataInputStream $data) : BmpInfoHeader
+    {
+        $infoHeaderSizeData = $data -> read(4);
+        $infoHeaderSize = unpack("V", $infoHeaderSizeData)[1];
+        switch ($infoHeaderSize) {
+            case self::BITMAPCOREHEADER_SIZE:
+                return self::readCoreHeader($data);
+            case 64:
+                throw new Exception("OS22XBITMAPHEADER not implemented");
+            case 16:
+                throw new Exception("OS22XBITMAPHEADER not implemented");
+            case self::BITMAPINFOHEADER_SIZE:
+                return self::readBitmapInfoHeader($data);
+            case 52:
+                throw new Exception("BITMAPV2INFOHEADER not implemented");
+            case 56:
+                throw new Exception("BITMAPV3INFOHEADER not implemented");
+            case 108:
+                throw new Exception("BITMAPV4HEADER not implemented");
+            case 124:
+                throw new Exception("BITMAPV5HEADER not implemented");
+            default:
+                throw new Exception("Info header size " . $infoHeaderSize . " is not supported.");
+        }
+    }
+
+    private static function readCoreHeader(DataInputStream $data) : BmpInfoHeader
+    {
+        $infoData = $data -> read(self::BITMAPCOREHEADER_SIZE - 4);
+        $fields = unpack("vwidth/vheight/vplanes/vbpp", $infoData);
+        return new BmpInfoHeader(self::BITMAPCOREHEADER_SIZE, $fields['width'], $fields['height'], $fields['planes'], $fields['bpp']);
+    }
+
+    private static function readBitmapInfoHeader(DataInputStream $data) : BmpInfoHeader
+    {
+        $infoData = $data -> read(self::BITMAPINFOHEADER_SIZE - 4);
+        $fields = unpack("Vwidth/Vheight/vplanes/vbpp/Vcompression/VcompressedSize/VhorizontalRes/VverticalRes/Vcolors/VimportantColors", $infoData);
+        return new BmpInfoHeader(self::BITMAPINFOHEADER_SIZE, $fields['width'], $fields['height'], $fields['planes'], $fields['bpp'], $fields['compression'], $fields['compressedSize'], $fields['horizontalRes'], $fields['verticalRes'], $fields['colors'], $fields['importantColors']);
+    }
+}
diff --git a/src/Mike42/GfxPhp/Codec/BmpCodec.php b/src/Mike42/GfxPhp/Codec/BmpCodec.php
@@ -2,10 +2,13 @@
 
 namespace Mike42\GfxPhp\Codec;
 
+use Mike42\GfxPhp\Codec\Bmp\BmpFile;
+use Mike42\GfxPhp\Codec\Common\DataBlobInputStream;
+use Mike42\GfxPhp\Codec\Gif\GifDataStream;
 use Mike42\GfxPhp\RasterImage;
 use Mike42\GfxPhp\RgbRasterImage;
 
-class BmpCodec implements ImageEncoder
+class BmpCodec implements ImageEncoder, ImageDecoder
 {
     protected static $instance = null;
     const INFO_HEADER_SIZE = 40;
@@ -71,6 +74,26 @@ public function getEncodeFormats(): array
         return ["bmp", "dib"];
     }
 
+    public function decode(string $blob): RasterImage
+    {
+        $data = DataBlobInputStream::fromBlob($blob);
+        $bmp = BmpFile::fromBinary($data);
+        return $bmp -> toRasterImage();
+    }
+
+    public function identify(string $blob): string
+    {
+        if (substr($blob, 0, 2) == BmpFile::BMP_SIGNATURE) {
+            return "bmp";
+        }
+        return "";
+    }
+
+    public function getDecodeFormats(): array
+    {
+        return ["bmp", "dib"];
+    }
+
     public static function getInstance()
     {
         if (self::$instance === null) {

diff --git a/src/Mike42/GfxPhp/Codec/ImageCodec.php b/src/Mike42/GfxPhp/Codec/ImageCodec.php
@@ -61,6 +61,7 @@ public static function getInstance() : ImageCodec
             $decoders = [
                 PngCodec::getInstance(),
                 GifCodec::getInstance(),
+                BmpCodec::getInstance(),
                 PnmCodec::getInstance(),
                 WbmpCodec::getInstance()
             ];