Document jpgtest decompress-only feature

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@292 632fc199-4ca6-4c93-a231-07263d6284db

ChangeLog.txt

@@ -8,6 +8,8 @@ README-turbo.txt for more details.  This feature was sponsored by CamTrace SAS.
 
 [3] TurboJPEG/OSS can now compress from/decompress to grayscale bitmaps.
 
+[4] jpgtest can now be used to test decompression performance only.
+
 
 Significant changes since 1.0.0
 ===============================

jpgtest.cxx

@@ -359,7 +359,8 @@ void dodecomptest(char *filename, BMPPIXELFORMAT pf, int bu, int useppm,
 
 void usage(char *progname)
 {
-	printf("USAGE: %s <Inputfile (BMP|PPM|JPG))> <%% Quality>\n\n", progname);
+	printf("USAGE: %s <Inputfile (BMP|PPM))> <%% Quality>\n", progname);
+	printf("       %s <Inputfile (JPG))>\n\n", progname);
 	printf("       [-tile]\n");
 	printf("       Test performance of the codec when the image is encoded\n");
 	printf("       as separate tiles of varying sizes.\n\n");