* Rename --rgb into --combine and add --split. Basic per-channel operations

are now possible:
      pipi src.png --split --contrast -.2 --combine -o dest.png

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2755 92316355-f0b4-4df1-b90c-862c8a59935f

pipi/context.c

@@ -373,7 +373,20 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...)
         ctx->images[ctx->nimages - 1] = pipi_rotate270(tmp);
         pipi_free(tmp);
     }
-    else if(!strcmp(cmd, "rgb"))
+    else if(!strcmp(cmd, "split"))
+    {
+        pipi_image_t *src;
+
+        if(ctx->nimages < 1)
+            return -1;
+        src = ctx->images[ctx->nimages - 1];
+        ctx->nimages += 2;
+        ctx->images[ctx->nimages - 3] = pipi_red(src);
+        ctx->images[ctx->nimages - 2] = pipi_green(src);
+        ctx->images[ctx->nimages - 1] = pipi_blue(src);
+        pipi_free(src);
+    }
+    else if(!strcmp(cmd, "combine"))
     {
         pipi_image_t *dst;
 

src/pipi.c

@@ -168,9 +168,14 @@ int main(int argc, char *argv[])
             if(pipi_command(ctx, "wrap") != 0)
                 return EXIT_FAILURE;
         }
-        else if(!strcmp(argv[0], "--rgb"))
+        else if(!strcmp(argv[0], "--combine"))
         {
-            if(pipi_command(ctx, "rgb") != 0)
+            if(pipi_command(ctx, "combine") != 0)
+                return EXIT_FAILURE;
+        }
+        else if(!strcmp(argv[0], "--split"))
+        {
+            if(pipi_command(ctx, "split") != 0)
                 return EXIT_FAILURE;
         }
         else if(!strcmp(argv[0], "--mean"))