Grayscale bitmap support in TurboJPEG/OSS

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@288 632fc199-4ca6-4c93-a231-07263d6284db

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 5f485d5ba2164f0d33ee93590831ffb4bb7aef6d..1cabc2c234446843d6fabefb066e4d114f42a996 100644 (file)
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -6,6 +6,8 @@ README-turbo.txt for more details.  This feature was sponsored by CamTrace SAS.
 
 [2] Created a new CMake-based build system for the Visual C++ and MinGW builds.
 
+[3] TurboJPEG/OSS can now compress from/decompress to grayscale bitmaps.
+
 
 Significant changes since 1.0.0
 ===============================

diff --git a/jpegut.c b/jpegut.c
index cec0f72949f6b2d7ce07209899c9836556b630c3..db46b6da4cbb9c8472ef800ce0e2b01b496a5230 100644 (file)
--- a/jpegut.c
+++ b/jpegut.c
@@ -46,6 +46,28 @@ void initbuf(unsigned char *buf, int w, int h, int ps, int flags)
                _i, j;
        if(flags&TJ_ALPHAFIRST) {roffset++;  goffset++;  boffset++;}
        memset(buf, 0, w*h*ps);
+       if(ps==1)
+       {
+               for(_i=0; _i<16; _i++)
+               {
+                       if(flags&TJ_BOTTOMUP) i=h-_i-1;  else i=_i;
+                       for(j=0; j<w; j++)
+                       {
+                               if(((_i/8)+(j/8))%2==0) buf[w*i+j]=255;
+                               else buf[w*i+j]=76;
+                       }
+               }
+               for(_i=16; _i<h; _i++)
+               {
+                       if(flags&TJ_BOTTOMUP) i=h-_i-1;  else i=_i;
+                       for(j=0; j<w; j++)
+                       {
+                               if(((_i/8)+(j/8))%2==0) buf[w*i+j]=0;
+                               else buf[w*i+j]=226;
+                       }
+               }
+               return;
+       }
        for(_i=0; _i<16; _i++)
        {
                if(flags&TJ_BOTTOMUP) i=h-_i-1;  else i=_i;
@@ -93,6 +115,7 @@ int checkbuf(unsigned char *buf, int w, int h, int ps, int subsamp, int flags)
        int roffset=(flags&TJ_BGR)?2:0, goffset=1, boffset=(flags&TJ_BGR)?0:2, i,
                _i, j;
        if(flags&TJ_ALPHAFIRST) {roffset++;  goffset++;  boffset++;}
+       if(ps==1) roffset=goffset=boffset=0;
        if(subsamp==TJ_GRAYSCALE)
        {
                for(_i=0; _i<16; _i++)
@@ -208,6 +231,7 @@ void gentestjpeg(tjhandle hnd, unsigned char *jpegbuf, unsigned long *size,
                if(ps==3) pixformat="RGB";
                else {if(flags&TJ_ALPHAFIRST) pixformat="ARGB";  else pixformat="RGBA";}
        }
+       if(ps==1) pixformat="Grayscale";
        printf("%s %s -> %s Q%d ... ", pixformat,
                (flags&TJ_BOTTOMUP)?"Bottom-Up":"Top-Down ", _subnamel[subsamp], qual);
 
@@ -247,6 +271,7 @@ void gentestbmp(tjhandle hnd, unsigned char *jpegbuf, unsigned long jpegsize,
                if(ps==3) pixformat="RGB";
                else {if(flags&TJ_ALPHAFIRST) pixformat="ARGB";  else pixformat="RGBA";}
        }
+       if(ps==1) pixformat="Grayscale";
        printf("JPEG -> %s %s ... ", pixformat, (flags&TJ_BOTTOMUP)?"Bottom-Up":"Top-Down ");
 
        _catch(tjDecompressHeader(hnd, jpegbuf, jpegsize, &_w, &_h));
@@ -292,6 +317,8 @@ void dotest(int w, int h, int ps, int subsamp, char *basefilename)
        gentestjpeg(hnd, jpegbuf, &size, w, h, ps, basefilename, subsamp, 100, 0);
        gentestbmp(dhnd, jpegbuf, size, w, h, ps, basefilename, subsamp, 100, 0);
 
+       if(ps==1) goto finally;
+
        gentestjpeg(hnd, jpegbuf, &size, w, h, ps, basefilename, subsamp, 100, TJ_BGR);
        gentestbmp(dhnd, jpegbuf, size, w, h, ps, basefilename, subsamp, 100, TJ_BGR);
 
@@ -379,6 +406,7 @@ int main(int argc, char *argv[])
 {
        dotest(35, 41, 3, TJ_444, "test");
        dotest(35, 41, 4, TJ_444, "test");
+       dotest(35, 41, 1, TJ_GRAYSCALE, "test");
        dotest(35, 41, 3, TJ_GRAYSCALE, "test");
        dotest(35, 41, 4, TJ_GRAYSCALE, "test");
        dotest1();

diff --git a/turbojpegl.c b/turbojpegl.c
index c3694c85e062d702913193c54b5c6f4c9452aeec..03833c504d04dd744775f0bddb1ae327a5353d09 100644 (file)
--- a/turbojpegl.c
+++ b/turbojpegl.c
@@ -1,6 +1,6 @@
 /* Copyright (C)2004 Landmark Graphics Corporation
  * Copyright (C)2005 Sun Microsystems, Inc.
- * Copyright (C)2009 D. R. Commander
+ * Copyright (C)2009-2010 D. R. Commander
  *
  * This library is free software and may be redistributed and/or modified under
  * the terms of the wxWindows Library License, Version 3.1 or (at your option)
@@ -124,7 +124,8 @@ DLLEXPORT int DLLCALL tjCompress(tjhandle h,
                || dstbuf==NULL || size==NULL
                || jpegsub<0 || jpegsub>=NUMSUBOPT || qual<0 || qual>100)
                _throw("Invalid argument in tjCompress()");
-       if(ps!=3 && ps!=4) _throw("This compressor can only take 24-bit or 32-bit RGB input");
+       if(ps!=3 && ps!=4 && ps!=1)
+               _throw("This compressor can only handle 24-bit and 32-bit RGB or 8-bit grayscale input");
        if(!j->initc) _throw("Instance has not been initialized for compression");
 
        if(pitch==0) pitch=width*ps;
@@ -133,8 +134,9 @@ DLLEXPORT int DLLCALL tjCompress(tjhandle h,
        j->cinfo.image_height = height;
        j->cinfo.input_components = ps;
 
+       if(ps==1) j->cinfo.in_color_space = JCS_GRAYSCALE;
        #if JCS_EXTENSIONS==1
-       j->cinfo.in_color_space = JCS_EXT_RGB;
+       else j->cinfo.in_color_space = JCS_EXT_RGB;
        if(ps==3 && (flags&TJ_BGR))
                j->cinfo.in_color_space = JCS_EXT_BGR;
        else if(ps==4 && !(flags&TJ_BGR) && !(flags&TJ_ALPHAFIRST))
@@ -287,7 +289,8 @@ DLLEXPORT int DLLCALL tjDecompress(tjhandle h,
        if(srcbuf==NULL || size<=0
                || dstbuf==NULL || width<=0 || pitch<0 || height<=0)
                _throw("Invalid argument in tjDecompress()");
-       if(ps!=3 && ps!=4) _throw("This compressor can only take 24-bit or 32-bit RGB input");
+       if(ps!=3 && ps!=4 && ps!=1)
+               _throw("This decompressor can only handle 24-bit and 32-bit RGB or 8-bit grayscale output");
        if(!j->initd) _throw("Instance has not been initialized for decompression");
 
        if(pitch==0) pitch=width*ps;
@@ -315,8 +318,9 @@ DLLEXPORT int DLLCALL tjDecompress(tjhandle h,
                else row_pointer[i]= &dstbuf[i*pitch];
        }
 
+       if(ps==1) j->dinfo.out_color_space = JCS_GRAYSCALE;
        #if JCS_EXTENSIONS==1
-       j->dinfo.out_color_space = JCS_EXT_RGB;
+       else j->dinfo.out_color_space = JCS_EXT_RGB;
        if(ps==3 && (flags&TJ_BGR))
                j->dinfo.out_color_space = JCS_EXT_BGR;
        else if(ps==4 && !(flags&TJ_BGR) && !(flags&TJ_ALPHAFIRST))