Update README files

README

@@ -99,6 +99,12 @@ from SjpegEncodeParam can be triggered from the keyboard.
 
 Please read the instructions in the INSTALL file.
 
+Basically, you can use the supplied Makefile or generate your build with
+cmake:
+
+  . `make -j`, or
+  . `mkdir build && cd build && cmake ../ && make -j`
+
 * Discussion list
 *****************
 

README.md

@@ -1,4 +1,4 @@
-                     ____ __   __ __  ____ ____  ____ 
+                     ____ __   __ __  ____ ____  ____
                     /  __\__) /  \  \/  _ \   / /  _ \
                    _\_   \  (/      /   __/  /_/   __/
                    \_____/___/__//_/\__/_/_____/_____/
@@ -21,80 +21,95 @@
 The main header is src/sjpeg.h.
 This is mainly just one function to call, defined in src/sjpeg.h
 
+```
 size_t SjpegCompress(const uint8_t* rgb, int width, int height,
                      int quality, uint8_t** out_data);
+```
 
 This function will make a lot of automatic decisions based on input samples.
 
 There is a more fine-tuned variant available too:
 
+```
 size_t SjpegEncode(const uint8_t* const data,
                    int W, int H, int stride,
                    uint8_t** const out_data,
                    int quality, int compression_method,
                    int yuv_mode);
+```
 
 as well as functions with a C++ string-based API.
 
 Also included in the library: some helper functions to inspect JPEG bitstream.
 They are meant to help re-processing a JPEG source:
-  SjpegDimensions(): quickly get the JPEG picture dimensions.
-  SjpegFindQuantizer(): return the quantization matrices
-  SjpegEstimateQuality(): return an estimate of the encoding quality
+  `SjpegDimensions()`: quickly get the JPEG picture dimensions.
+  `SjpegFindQuantizer()`: return the quantization matrices
+  `SjpegEstimateQuality()`: return an estimate of the encoding quality
 
 The library comes primarily with a plain-C API, but a C++ version is available
-too, that uses std::string as interface.
+too, that uses `std::string` as interface.
 
 
-# SjpegEncodeParam interface:
+## SjpegEncodeParam interface:
 
 This should be the most fine-tuned use of the library: SjpegEncodeParam gives
-access to a lot of fine controls (C++ only). See src/sjpeg.h for details.
+access to a lot of fine controls (C++ only). See `src/sjpeg.h` for details.
 
 In particular, using SjpegEncodeParam is the recommended way of re-compressing
 a JPEG input. Here is the recipe:
-  * use SjpegFindQuantizer to extract the quantization matrices from the source
-  * use SjpegEncodeParam::SetQuantMatrix() to transfer them to the encoding
-    parameters (with a reduction factor if necessary)
-  * call sjpeg::SjpegEncode() with this parameter
 
-Alternatively, one can use SjpegEstimateQuality() and
-SjpegEncodeParam::SetQuality() to pass a quality factor instead of the matrices.
+* use `SjpegFindQuantizer` to extract the quantization matrices from the source
+* use `SjpegEncodeParam::SetQuantMatrix()` to transfer them to the encoding parameters (with a reduction factor if necessary)
+* call `sjpeg::SjpegEncode()` with this parameter
 
-SjpegEncodeParam is also useful for transfering some metadata to the final
+Alternately, one can use `SjpegEstimateQuality()` and
+`SjpegEncodeParam::SetQuality()` to pass a quality factor instead of the matrices.
+
+`SjpegEncodeParam` is also useful for transfering some metadata to the final
 JPEG bitstream.
 
-# 'Riskiness' score:
+## 'Riskiness' score:
 
 The riskiness score is a decision score to help decide between using YUV 4:2:0
 and YUV 4:4:4 downsampling. The function to call is:
 
+```
  int SjpegRiskiness(const uint8_t* rgb, int width, int height, int step, float* risk);
+```
 
 which returns a recommendation for 'yuv_mode' to use in the above API.
 
-# The 'sjpeg' command line tool:
+## The 'sjpeg' command line tool:
+
+`examples/sjpeg` is a very simple tool to compress a PNG/JPEG file to JPEG.
 
-examples/sjpeg is a very simple tool to compress a PNG/JPEG file to JPEG.
+`sjpeg in.png -o out.jpg -q 70     # compress the PNG source with quality 70`
 
-sjpeg in.png -o out.jpg -q 70     # compress the PNG source with quality 70
-sjpeg in.jpg -o out.jpg -r 90     # recompress JPEG input to ~90%
+`sjpeg in.jpg -o out.jpg -r 90     # recompress JPEG input to ~90% `
 
 sjpeg has various options to change the encoding method. Just try `sjpeg -h`.
 
-# The 'vjpeg' command line tool:
+## The 'vjpeg' command line tool:
+
+![vjpeg UI](https://github.com/webmproject/sjpeg/examples/vjpeg_sample.jpg "the vjpeg interface")
 
 examples/vjpeg is a (non-essential) visualization tool, built with OpenGL/GLUT.
 It allows changing the compression parameters with the keyboard, and visually
 inspect the result. This is mostly educational, since most of the parameters
-from SjpegEncodeParam can be triggered from the keyboard.
+from `SjpegEncodeParam` can be triggered from the keyboard.
 
 # Building the library and tools:
 
 Please read the instructions in the INSTALL file.
 
+Basically, you can use the supplied Makefile or generate your build with
+cmake:
+
+* `make -j`, or
+* `mkdir build && cd build && cmake ../ && make -j`
+
 # Discussion list
 
 The following forum can be used to report bugs or just discuss sjpeg:
 
-https://groups.google.com/forum/#!forum/sjpeg
+[https://groups.google.com/forum/#!forum/sjpeg]([https://groups.google.com/forum/#!forum/sjpeg)