diff --git a/src/bin/jp2/opj_compress.c b/src/bin/jp2/opj_compress.c
index aba30ef9..96401941 100644
--- a/src/bin/jp2/opj_compress.c
+++ b/src/bin/jp2/opj_compress.c
@@ -467,7 +467,8 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
         {"POC",REQ_ARG, NULL ,'P'},
         {"ROI",REQ_ARG, NULL ,'R'},
         {"jpip",NO_ARG, NULL, 'J'},
-        {"mct",REQ_ARG, NULL, 'Y'}
+        {"mct",REQ_ARG, NULL, 'Y'},
+        {"version",NO_ARG, NULL, 'v'}
     };
 
     /* parse the command line */
@@ -475,7 +476,7 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
         #ifdef USE_JPWL
             "W:"
         #endif /* USE_JPWL */
-            "h";
+            "hv";
 
     totlen=sizeof(long_option);
     img_fol->set_out_format=0;
@@ -502,8 +503,8 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
                 break;
             default:
                 fprintf(stderr,
-                        "!! Unrecognized format for infile : %s "
-                        "[accept only *.pnm, *.pgm, *.ppm, *.pgx, *png, *.bmp, *.tif, *.raw or *.tga] !!\n\n",
+                        "[ERROR] Unknown input file format: %s \n"
+                        "        Known file formats are *.pnm, *.pgm, *.ppm, *.pgx, *png, *.bmp, *.tif, *.raw or *.tga\n",
                         infile);
                 return 1;
             }
@@ -842,6 +843,13 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
 
             /* ----------------------------------------------------- */
 
+        case 'v':			/* display the openjpeg library version in use */
+            fprintf(stdout,"This is the opj_compress utility from the OpenJPEG project.\n"
+                    "It has been compiled against openjp2 library v%s.\n",opj_version());
+            return 1;
+
+            /* ----------------------------------------------------- */
+
         case 'P':			/* POC */
         {
             int numpocs = 0;		/* number of progression order change (POC) default 0 */
@@ -1412,37 +1420,38 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
 
 
         default:
-            fprintf(stderr, "ERROR -> Command line not valid\n");
-            return 1;
+            fprintf(stderr, "[WARNING] An invalid option has been ignored\n");
+            break;
         }
     }while(c != -1);
 
     if(img_fol->set_imgdir == 1){
         if(!(parameters->infile[0] == 0)){
-            fprintf(stderr, "Error: options -ImgDir and -i cannot be used together !!\n");
+            fprintf(stderr, "[ERROR] options -ImgDir and -i cannot be used together !!\n");
             return 1;
         }
         if(img_fol->set_out_format == 0){
-            fprintf(stderr, "Error: When -ImgDir is used, -OutFor <FORMAT> must be used !!\n");
+            fprintf(stderr, "[ERROR] When -ImgDir is used, -OutFor <FORMAT> must be used !!\n");
             fprintf(stderr, "Only one format allowed! Valid formats are j2k and jp2!!\n");
             return 1;
         }
         if(!((parameters->outfile[0] == 0))){
-            fprintf(stderr, "Error: options -ImgDir and -o cannot be used together !!\n");
+            fprintf(stderr, "[ERROR] options -ImgDir and -o cannot be used together !!\n");
             fprintf(stderr, "Specify OutputFormat using -OutFor<FORMAT> !!\n");
             return 1;
         }
     }else{
         if((parameters->infile[0] == 0) || (parameters->outfile[0] == 0)) {
-            fprintf(stderr, "Example: %s -i image.ppm  -o image.j2k\n",argv[0]);
-            fprintf(stderr, "    Try: %s -h\n",argv[0]);
+            fprintf(stderr, "[ERROR] Required parameters are missing\n"
+                            "Example: %s -i image.j2k -o image.pgm\n",argv[0]);
+            fprintf(stderr, "   Help: %s -h\n",argv[0]);
             return 1;
         }
     }
 
     if ( (parameters->decod_format == RAW_DFMT && raw_cp->rawWidth == 0)
          || (parameters->decod_format == RAWL_DFMT && raw_cp->rawWidth == 0)) {
-        fprintf(stderr,"\nError: invalid raw image parameters\n");
+        fprintf(stderr,"[ERROR] invalid raw image parameters\n");
         fprintf(stderr,"Please use the Format option -F:\n");
         fprintf(stderr,"-F rawWidth,rawHeight,rawComp,rawBitDepth,s/u (Signed/Unsigned)\n");
         fprintf(stderr,"Example: -i lena.raw -o lena.j2k -F 512,512,3,8,u\n");
@@ -1452,7 +1461,7 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
 
     if ((parameters->cp_disto_alloc || parameters->cp_fixed_alloc || parameters->cp_fixed_quality)
             && (!(parameters->cp_disto_alloc ^ parameters->cp_fixed_alloc ^ parameters->cp_fixed_quality))) {
-        fprintf(stderr, "Error: options -r -q and -f cannot be used together !!\n");
+        fprintf(stderr, "[ERROR] options -r -q and -f cannot be used together !!\n");
         return 1;
     }				/* mod fixed_quality */
 
@@ -1465,7 +1474,7 @@ static int parse_cmdline_encoder(int argc, char **argv, opj_cparameters_t *param
 
     if((parameters->cp_tx0 > parameters->image_offset_x0) || (parameters->cp_ty0 > parameters->image_offset_y0)) {
         fprintf(stderr,
-                "Error: Tile offset dimension is unnappropriate --> TX0(%d)<=IMG_X0(%d) TYO(%d)<=IMG_Y0(%d) \n",
+                "[ERROR] Tile offset dimension is unnappropriate --> TX0(%d)<=IMG_X0(%d) TYO(%d)<=IMG_Y0(%d) \n",
                 parameters->cp_tx0, parameters->image_offset_x0, parameters->cp_ty0, parameters->image_offset_y0);
         return 1;
     }
@@ -1803,7 +1812,7 @@ int main(int argc, char **argv) {
             return 1;
         }
 
-        fprintf(stderr,"Generated outfile %s\n",parameters.outfile);
+        fprintf(stdout,"[INFO] Generated outfile %s\n",parameters.outfile);
         /* close and free the byte stream */
         opj_stream_destroy_v3(l_stream);
 
diff --git a/src/bin/jp2/opj_decompress.c b/src/bin/jp2/opj_decompress.c
index 59edb4a4..1164f061 100644
--- a/src/bin/jp2/opj_decompress.c
+++ b/src/bin/jp2/opj_decompress.c
@@ -332,6 +332,7 @@ int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *parameters,i
 	opj_option_t long_option[]={
 		{"ImgDir",REQ_ARG, NULL ,'y'},
 		{"OutFor",REQ_ARG, NULL ,'O'},
+        {"version",NO_ARG, NULL ,'v'}
 	};
 
 	const char optlist[] = "i:o:r:l:x:d:t:"
@@ -341,7 +342,7 @@ int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *parameters,i
 					"W:"
 #endif /* USE_JPWL */
 /* <<UniPG */
-			"h"		;
+            "hv"		;
 	totlen=sizeof(long_option);
 	img_fol->set_out_format = 0;
 	do {
@@ -367,7 +368,8 @@ int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *parameters,i
 						return 1;
 					default:
 						fprintf(stderr, 
-							"!! Unrecognized format for infile: %s [accept only *.j2k, *.jp2, *.jpc or *.jpt] !!\n\n", 
+                            "[ERROR] Unknown input file format: %s \n"
+                            "        Known file formats are *.j2k, *.jp2, *.jpc or *.jpt\n",
 							infile);
 						return 1;
 				}
@@ -472,10 +474,17 @@ int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *parameters,i
 				decode_help_display();
 				return 1;				
 
-				/* ------------------------------------------------------ */
+                /* ------------------------------------------------------ */
+
+             case 'v':			/* display the openjpeg library version in use */
+            fprintf(stdout,"This is the opj_decompress utility from the OpenJPEG project.\n"
+                    "It has been compiled against openjp2 library v%s.\n",opj_version());
+            return 1;
+
+            /* ----------------------------------------------------- */
 
 			case 'y':			/* Image Directory path */
-				{
+                {
 					img_fol->imgdirpath = (char*)malloc(strlen(opj_optarg) + 1);
 					strcpy(img_fol->imgdirpath,opj_optarg);
 					img_fol->set_imgdir=1;
@@ -589,31 +598,32 @@ int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *parameters,i
 
 				/* ----------------------------------------------------- */
 			
-			default:
-				fprintf(stderr,"WARNING -> this option is not valid \"-%c %s\"\n",c, opj_optarg);
-				break;
+        default:
+            fprintf(stderr, "[WARNING] An invalid option has been ignored\n");
+            break;
 		}
 	}while(c != -1);
 
 	/* check for possible errors */
 	if(img_fol->set_imgdir==1){
 		if(!(parameters->infile[0]==0)){
-			fprintf(stderr, "Error: options -ImgDir and -i cannot be used together !!\n");
+            fprintf(stderr, "[ERROR] options -ImgDir and -i cannot be used together !!\n");
 			return 1;
 		}
 		if(img_fol->set_out_format == 0){
-			fprintf(stderr, "Error: When -ImgDir is used, -OutFor <FORMAT> must be used !!\n");
+            fprintf(stderr, "[ERROR] When -ImgDir is used, -OutFor <FORMAT> must be used !!\n");
 			fprintf(stderr, "Only one format allowed! Valid format PGM, PPM, PNM, PGX, BMP, TIF, RAW and TGA!!\n");
 			return 1;
 		}
 		if(!((parameters->outfile[0] == 0))){
-			fprintf(stderr, "Error: options -ImgDir and -o cannot be used together !!\n");
+            fprintf(stderr, "[ERROR] options -ImgDir and -o cannot be used together !!\n");
 			return 1;
 		}
 	}else{
 		if((parameters->infile[0] == 0) || (parameters->outfile[0] == 0)) {
-			fprintf(stderr, "Example: %s -i image.j2k -o image.pgm\n",argv[0]);
-			fprintf(stderr, "    Try: %s -h\n",argv[0]);
+            fprintf(stderr, "[ERROR] Required parameters are missing\n"
+                            "Example: %s -i image.j2k -o image.pgm\n",argv[0]);
+            fprintf(stderr, "   Help: %s -h\n",argv[0]);
 			return 1;
 		}
 	}
@@ -877,81 +887,81 @@ int main(int argc, char **argv)
 		switch (parameters.cod_format) {
 		case PXM_DFMT:			/* PNM PGM PPM */
 			if (imagetopnm(image, parameters.outfile)) {
-				fprintf(stderr,"Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 
 		case PGX_DFMT:			/* PGX */
 			if(imagetopgx(image, parameters.outfile)){
-				fprintf(stderr,"Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 
 		case BMP_DFMT:			/* BMP */
 			if(imagetobmp(image, parameters.outfile)){
-				fprintf(stderr,"Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 #ifdef OPJ_HAVE_LIBTIFF
 		case TIF_DFMT:			/* TIFF */
 			if(imagetotif(image, parameters.outfile)){
-				fprintf(stderr,"Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 #endif /* OPJ_HAVE_LIBTIFF */
 		case RAW_DFMT:			/* RAW */
 			if(imagetoraw(image, parameters.outfile)){
-				fprintf(stderr,"Error generating raw file. Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Error generating raw file. Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Successfully generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 
 		case RAWL_DFMT:			/* RAWL */
 			if(imagetorawl(image, parameters.outfile)){
-				fprintf(stderr,"Error generating rawl file. Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Error generating rawl file. Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Successfully generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 
 		case TGA_DFMT:			/* TGA */
 			if(imagetotga(image, parameters.outfile)){
-				fprintf(stderr,"Error generating tga file. Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Error generating tga file. Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Successfully generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 #ifdef OPJ_HAVE_LIBPNG
 		case PNG_DFMT:			/* PNG */
 			if(imagetopng(image, parameters.outfile)){
-				fprintf(stderr,"Error generating png file. Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Error generating png file. Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 			}
 			else {
-				fprintf(stdout,"Successfully generated Outfile %s\n",parameters.outfile);
+                fprintf(stdout,"[INFO] Generated Outfile %s\n",parameters.outfile);
 			}
 			break;
 #endif /* OPJ_HAVE_LIBPNG */
@@ -959,7 +969,7 @@ int main(int argc, char **argv)
  * and OPJ_HAVE_LIBTIF or OPJ_HAVE_LIBPNG is undefined
 */
 			default:
-				fprintf(stderr,"Outfile %s not generated\n",parameters.outfile);
+                fprintf(stderr,"[ERROR] Outfile %s not generated\n",parameters.outfile);
         failed = 1;
 		}
 
diff --git a/src/bin/jp2/opj_dump.c b/src/bin/jp2/opj_dump.c
index 6abbec78..3121aa4f 100644
--- a/src/bin/jp2/opj_dump.c
+++ b/src/bin/jp2/opj_dump.c
@@ -298,12 +298,13 @@ static int parse_cmdline_decoder(int argc, char **argv, opj_dparameters_t *param
 					case JP2_CFMT:
 						break;
 					case JPT_CFMT:
-						break;
-					default:
-						fprintf(stderr, 
-							"!! Unrecognized format for infile : %s [accept only *.j2k, *.jp2, *.jpc or *.jpt] !!\n\n", 
-							infile);
-						return 1;
+                    break;
+                default:
+                    fprintf(stderr,
+                            "[ERROR] Unknown input file format: %s \n"
+                            "        Known file formats are *.j2k, *.jp2, *.jpc or *.jpt\n",
+                            infile);
+                    return 1;
 				}
 				strncpy(parameters->infile, infile, sizeof(parameters->infile)-1);
 			}