+ sampler.[ch]

src/sampler.c

@@ -0,0 +1,90 @@
+#include "common.h"
+#include "database.h"
+#include "sampler.h"
+
+#include <wand/magick_wand.h>
+
+int
+imdb_sample(imdb_rec_t * const rec,
+                  char * const source)
+{
+  MagickWand *wand = NULL;
+  MagickPassFail status = MagickPass;
+  ExceptionType severity = 0;
+  unsigned long w = 0, h = 0;
+  char *description = NULL;
+  size_t buf_size = 64 * sizeof(char);
+  unsigned char *buf = NULL;
+
+  InitializeMagick("/"); /* FIXME */
+  wand = NewMagickWand();
+  if (status == MagickPass)
+    status = MagickReadImage(wand, source);
+
+  if (status == MagickPass)
+    w = MagickGetImageHeight(wand);
+
+  if (status == MagickPass)
+    h = MagickGetImageHeight(wand);
+
+  /* 2 -> 160 : width, "cols" */
+  /* 3 -> 160 : width, "rows" */
+  if (status == MagickPass)
+    status = MagickSampleImage(wand, 160, 160);
+
+  /* TODO: color maps */
+
+  /* 2 -> 256 : number of colors */
+  /* 3 ->   0 : treedepth     -> auto */
+  /* 4 ->   0 : dither        -> none */
+  /* 5 ->   0 : measure_error -> none */
+  if (status == MagickPass)
+    status = MagickQuantizeImage(wand, 256, GRAYColorspace, 0, 0, 0);
+
+  /* 2 -> 3 : radius, in pixels */
+  /* 3 -> 2 : "for reasonable results, radius should be larger than sigma" */
+  if (status == MagickPass)
+    status = MagickBlurImage(wand, 3, 2);
+
+  if (status == MagickPass)
+    status = MagickNormalizeImage(wand);
+
+  if (status == MagickPass)
+    status = MagickEqualizeImage(wand);
+
+  /* 2 -> 16 : width, "cols" */
+  /* 3 -> 16 : width, "rows" */
+  if (status == MagickPass)
+    status = MagickSampleImage(wand, 16, 16);
+
+  /* 2 -> 0.5 : threshold (tune?) */
+  if (status == MagickPass)
+    status = MagickThresholdImage(wand, 0.5);
+
+  if (status == MagickPass)
+    status = MagickSetImageType(wand, BilevelType);
+
+  if (status == MagickPass)
+    status = MagickSetImageFormat(wand, "BMP");
+
+  if (status == MagickPass)
+    buf = MagickWriteImageBlob(wand, &buf_size);
+
+  if (status != MagickPass) {
+    description = MagickGetException(wand, &severity);
+    fprintf(stderr, "%03d %.1024s\n", severity, description); /* FIXME */
+  }
+
+  DestroyMagickWand(wand);
+  DestroyMagick();
+
+  if (status != MagickPass)
+    return -1;
+
+  rec->data[REC_OFF_RU] = 1;
+  *((uint16_t *) &rec->data[REC_OFF_IW]) = (uint16_t) w;
+  *((uint16_t *) &rec->data[REC_OFF_IH]) = (uint16_t) h;
+  memcpy(&rec->data[REC_OFF_BM], buf, 32);
+
+  return 0;
+}

src/sampler.h

@@ -0,0 +1,8 @@
+#ifndef HAS_SAMPLER_H
+#define HAS_SAMPLER_H 1
+
+int
+imdb_sample(imdb_rec_t * const rec,
+                  char * const source);
+
+#endif /* HAS_SAMPLER_H */