Changeset 38326 for branches/eam_branches/ohana.20150429/src/libfits/matrix/F_compress_utils.c

Timestamp:

May 26, 2015, 4:29:20 PM (11 years ago)

Author:

eugene

Message:

updating compression functions

File:

• branches/eam_branches/ohana.20150429/src/libfits/matrix/F_compress_utils.c (modified) (1 diff)

branches/eam_branches/ohana.20150429/src/libfits/matrix/F_compress_utils.c

@@ -13 +13 @@
 // XXX inconsistency between data element size between compressed data, uncompressed data, 
 // and output pixel data.....
+
+// need a structure to describe tiles, current tile?
+
+typedef struct {
+  int *ztile; // max size of a tile (edge tiles may be smaller)
+  int *otile; // counter for current tile (eg, for (2,3,0) otile[0] = 2, otile[1] = 3, otile[2] = 0)
+  int *ntile; // number of tiles in dimension [i]
+} ImageTile;
+
+// advance the otile counter. 
+int gfits_imtile_next (Matrix *matrix, int *ztile, int *ntile, int *otile) {
+
+  int i;
+
+  // update the tile counters, carrying to the next dimension if needed
+  for (i = 0; i < matrix->Naxes; i++) {
+    otile[i] ++;
+    if (otile[i] == ntile[i]) {
+      if (i == matrix->Naxes - 1) return FALSE;
+      otile[i] = 0;
+    } else {
+      return TRUE;
+    }
+  }
+  return TRUE;
+}
+
+// how many tiles needed for this image (given ztile[])
+int gfits_imtile_start (Matrix *matrix, int *otile) {
+
+  int i;
+
+  // update the tile counters, carrying to the next dimension if needed
+  for (i = 0; i < matrix->Naxes; i++) {
+    otile[i] = 0;
+  }
+}
+
+// how many tiles needed for this image (given ztile[])
+int gfits_imtile_count (Matrix *matrix, int *ztile, int *ntile) {
+
+  int i;
+
+  int Ntiles = 1;
+  for (i = 0; i < matrix->Naxes; i++) {
+    ntile[i] = (matrix->Naxis[i] % ztile[i]) ? (matrix->Naxis[i] / ztile[i] + 1) : (matrix->Naxis[i] / ztile[i]);
+    Ntiles *= ntile[i];
+  }
+  
+  return (Ntiles);
+}
+
+// how many tiles needed for this image (given ztile[])
+int gfits_imtile_maxsize (Matrix *matrix, int *ztile) {
+
+  int i;
+
+  int max_tile_size = 1;
+  for (i = 0; i < matrix->Naxes; i++) {
+    max_tile_size *= ztile[i];
+  }
+  
+  return (max_tile_size);
+}
 
 // true sizes of this tile (in pixels)