Added support for directly reading standard JPEG input images.

Implementation uses libjpeg's partial decoding and DCT-scaling functions to optimize decoding as much as is possible and supports ICC, XMP and EXIF metadata.
Note that JPEG does not support multi-resolution encoding, so decoding will be slower than reading TIFF or JPEG2000, especially for large images.

ChangeLog

@@ -1,3 +1,10 @@
+25/09/2024:
+	- Added support for directly reading standard JPEG input images. Implementation uses libjpeg's partial decoding
+	  and DCT-scaling functions to optimize decoding as much as is possible and supports ICC, XMP and EXIF metadata.
+	  Note that JPEG does not support multi-resolution encoding, so decoding will be slower than reading TIFF
+	  or JPEG2000, especially for large images.
+
+
 24/09/2024:
 	- Added TIFF codec version reporting in logfile and updated return signature for getCodecVersion() function.
 	  Also code cleanups for OpenJPEGImage and KakaduImage classes.

README

@@ -21,7 +21,7 @@ FEATURES
 * Fast lightweight FastCGI server
 * High performance with inbuilt configurable cache
 * Support for extremely large images: tera-pixel and multi gigapixel support
-* TIFF and JPEG2000 input support
+* TIFF, JPEG2000 and JPEG input support
 * JPEG, PNG, WebP and AVIF output support: export of whole or regions of images at any size
 * Supports IIP, Zoomify, DeepZoom and IIIF API's
 * 1, 8, 16 and 32 bit image support including 32 bit floating point support
@@ -469,13 +469,13 @@ IMAGES
 ------
 
 ### Image Input Formats
-Input images must be in either tiled multi-resolution (pyramid) TIFF format or in JPEG2000 format. See https://iipimage.sourceforge.io/documentation/images for details on how to create appropriate images.
+Input images must be in either tiled multi-resolution (pyramid) TIFF format, in JPEG2000 or in JPEG format. See https://iipimage.sourceforge.io/documentation/images for details on how to create appropriate images.
 
 ### Image Input Paths
 The images paths given to the server via the FIF command for the IIP API or in the IIIF, Deepzoom or Zoomify  requests must be absolute paths on the server machine (eg. FIF=/images/test.tif) and not paths relative to the web server document root location. Images do not, therefore, need to be directly accessible through the web server. The FILESYSTEM_PREFIX configuration parameter can be used to avoid overly long image paths. Make sure the iipsrv process owner is able to access and read the images!
 
 ### Output Images
-iipsrv can transcode input images in TIFF or JPEG2000 to JPEG, PNG or WebP format. See the API documentation for details on how to use iipsrv: https://iipimage.sourceforge.io/documentation/protocol
+iipsrv can transcode input images in TIFF, JPEG2000 or JPEG to JPEG, PNG, WebP or AVIF format. See the API documentation for details on how to use iipsrv: https://iipimage.sourceforge.io/documentation/protocol
 
 
 

configure.ac

@@ -83,11 +83,12 @@ AC_LANG_POP([C++])
 # Enable debugging
 AC_ARG_ENABLE([debug-mode],
               [  --enable-debug-mode     enable debugging mode (no FCGI)],
-              [AC_DEFINE(DEBUG)
-	       AC_DEFINE(KAKADU_DEBUG)
-               AC_DEFINE(OPENJPEG_DEBUG)
-               DEBUG=true
-	       AC_MSG_RESULT([configure: enabling debug mode])]
+		AC_DEFINE(DEBUG)
+		AC_DEFINE(KAKADU_DEBUG)
+		AC_DEFINE(OPENJPEG_DEBUG)
+		AC_DEFINE(JPEG_DEBUG)
+		DEBUG=true
+		AC_MSG_RESULT([configure: enabling debug mode])]
 )
 
 

src/FIF.cc

@@ -24,6 +24,7 @@
 #include "URL.h"
 #include "Environment.h"
 #include "TPTImage.h"
+#include "JPEGImage.h"
 
 #ifdef HAVE_KAKADU
 #include "KakaduImage.h"
@@ -134,6 +135,10 @@ void FIF::run( Session* session, const string& src ){
       if( session->loglevel >= 2 ) *(session->logfile) << "FIF :: TIFF image detected" << endl;
       *session->image = new TPTImage( test );
     }
+    else if( format == ImageEncoding::JPEG ){
+      if( session->loglevel >= 2 ) *(session->logfile) << "FIF :: JPEG image detected" << endl;
+      *session->image = new JPEGImage( test );
+    }
 #if defined(HAVE_KAKADU) || defined(HAVE_OPENJPEG)
     else if( format == ImageEncoding::JPEG2000 ){
       if( session->loglevel >= 2 )

src/IIPImage.cc

@@ -3,7 +3,7 @@
 
 /*  IIP fcgi server module
 
-    Copyright (C) 2000-2023 Ruven Pillay.
+    Copyright (C) 2000-2024 Ruven Pillay.
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -137,8 +137,12 @@ void IIPImage::testImageType()
     static const unsigned char lbigtiff[4] = {0x4D,0x4D,0x00,0x2B}; // Little Endian BigTIFF
     static const unsigned char bbigtiff[4] = {0x49,0x49,0x2B,0x00}; // Big Endian BigTIFF
 
+    // Magic file signature for JPEG
+    static const unsigned char jpeg[3] = {0xFF,0xDA,0xFF};
+
     // Compare our header sequence to our magic byte signatures
     if( memcmp( header, j2k, 10 ) == 0 ) format = ImageEncoding::JPEG2000;
+    else if( memcmp( header, jpeg, 3 ) ) format = ImageEncoding::JPEG;
     else if( memcmp( header, stdtiff, 3 ) == 0
 	     || memcmp( header, lsbtiff, 4 ) == 0 || memcmp( header, msbtiff, 4 ) == 0
 	     || memcmp( header, lbigtiff, 4 ) == 0 || memcmp( header, bbigtiff, 4 ) == 0 ){