README update

README.md

@@ -2,15 +2,7 @@
 creates di/tri/n-typch images from input files; scales them so them fit on the final image which can be a specified image size or an image size determined based on image inputs.
 
 ## Compiling / Dependancies
-This util depends on `ImageMagick` and `exiv2` - to complie:
-```
-g++ -DGEN_EXIF -DNEED_UCHAR_UINT_T \
-    $(pkg-config Magick++ --cflags) $(pkg-config exiv2 --cflags) \
-    diptych.cc \
-    $(pkg-config Magick++ --libs) $(pkg-config exiv2 --libs) \
-  -o diptych
-```
-Remove `-DGEN_EXIF` and references to `pkg-config exiv2` if exif info is not required in the output.
+This util depends on `C++ 17`, `ImageMagick` and optionally `exiv2` which will preserving common EXIF amognst the input images onto the final output image.
 
 ## Example Usage
 ### Typical ###
@@ -26,20 +18,17 @@ diptych -O 300 -B 10 -b 50 -C black -s 1:1  blue.jpg red.jpg -o final.jpg
 Resulting in an 300x185 image that is scaled to the requested output (note the size of text on 'red')
 ![Alt text](doc/final.jpg?raw=true "final.jpg")
 
-To create a vertical dipytch using the same files above, use `-s 2`
-
-### Resizing and adding Borders ###
-whilst this can be done with `ImageMagick` directly, getting the syntax correct has always annoyed me.  To do the same with this util:
+To create a _vertical dipytch_ (stacked on top of each other) using the same files above, use `-s 2`
 
+### Resizing, adding Borders, output quality ###
 ```
-diptych -O 480 -B 20 -b 35 -C white -q 85 original.jpg -o scaled.jpg
+diptych \
+    -O 1000 -B 20 -b 35 -C white -q 85 \
+    -s 2:1 a.jpg b.jpg c.jpg \
+  -o x.jpg
 ```
-This will scale (`-O`) the original image to 480pxls on the longest edge which includes the boders as specified.  The quality (`-q`) of the image is set of 85%.
-
-### Extended ###
-Slightly more complex renderings can be acheived via `-s`.
+This will scale (`-O`) the combined images to 480 pixels on the longest edge which includes the boders as specified.  The quality (`-q`) of the image is set of 85%.  All the `ImageMagick` resize scaling (_filter_) algorithms can be specified when scaling via `-f <IM filter name>`.
 
-```
-diptych -O 1024 -B 20 -b 35 -C white -s 2:1  a.jpg b.jpg c.jpg -o x.jpg
-```
 This will produce a vertical image (stacking `a.jpg` and `b.jpg`) and then using that result to create a horizontal diptypch with `c.jpg` - the output will be scalled so that all images proportions will fit the final out.
+
+We can also specify a single image to scale, resize, add borders etc if desired.