o Use GraphicsMagick instead of ImageMagick as it scales jpgs correctly

  and also uses less CPU

Makefile

@@ -12,8 +12,8 @@ RGB_LIBRARY=$(RGB_LIBDIR)/lib$(RGB_LIBRARY_NAME).a
 LDFLAGS+=-L$(RGB_LIBDIR) -l$(RGB_LIBRARY_NAME) -lrt -lm -lpthread
 
 # Imagemagic flags, only needed if actually compiled.
-MAGICK_CXXFLAGS=`Magick++-config --cppflags --cxxflags`
-MAGICK_LDFLAGS=`Magick++-config --ldflags --libs`
+MAGICK_CXXFLAGS=`GraphicsMagick++-config --cppflags --cxxflags`
+MAGICK_LDFLAGS=`GraphicsMagick++-config --ldflags --libs`
 
 all : $(BINARIES)
 

README.md

@@ -189,9 +189,9 @@ clears the screen (if you want to display an empty line, just send a space).
 
 One of the possibly useful demo applications is an image viewer that
 reads all kinds of image formats, including animated gifs. It is not compiled
-by default, as you need to install the imagemagick dependencies first:
+by default, as you need to install the GraphicsMagick dependencies first:
 
-     sudo aptitude install libmagick++-dev
+     sudo aptitude install libgraphicsmagick++1-dev
      make led-image-viewer
 
 Then, you can run it with any common image format:

led-image-viewer.cc

@@ -29,7 +29,7 @@
 
 #include <vector>
 #include <Magick++.h>
-#include <magick/quantum.h>
+#include <magick/image.h>
 
 using rgb_matrix::GPIO;
 using rgb_matrix::FrameCanvas;
@@ -58,9 +58,9 @@ class PreprocessedFrame {
         CoordinateMapping(x, y, &drawX, &drawY);
         if (c.alphaQuantum() == 0) {
           output->SetPixel(drawX, drawY,
-                           MagickCore::ScaleQuantumToChar(c.redQuantum()),
-                           MagickCore::ScaleQuantumToChar(c.greenQuantum()),
-                           MagickCore::ScaleQuantumToChar(c.blueQuantum()));
+                           ScaleQuantumToChar(c.redQuantum()),
+                           ScaleQuantumToChar(c.greenQuantum()),
+                           ScaleQuantumToChar(c.blueQuantum()));
         }
       }
     }
@@ -159,6 +159,8 @@ static int usage(const char *progname) {
 }
 
 int main(int argc, char *argv[]) {
+  Magick::InitializeMagick(*argv);
+
   int rows = 32;
   int chain = 1;
   int parallel = 1;