1 files changed, 115 insertions, 0 deletions
diff --git a/src/kernels/morphology.cl b/src/kernels/morphology.cl
new file mode 100644
index 0000000..af76b58
--- /dev/null
+++ b/src/kernels/morphology.cl
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2011-2019 Karlsruhe Institute of Technology
+ *
+ * This file is part of Ufo.
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Set mask to 1 if value exceeds threshold. If sgn is -1, value has to be below
+ * threshold, if it is 1 it has to be above threshold, if it is 0 absolute value
+ * is compared.
+ */
+kernel void
+set_above_threshold (global float *input,
+                         global float *output,
+                         const float threshold,
+                         const int sgn)
+{
+    int index = get_global_id (1) * get_global_size (0) + get_global_id (0);
+    float value = input[index];
+    if (!sgn) {
+        value = fabs (value) - threshold;
+    } else {
+        value = sgn * (value - threshold);
+    }
+
+    output[index] = value > 0 ? 1 : 0;
+}
+
+kernel void
+set_to_ones (global float *values)
+{
+    int x = get_global_id (0) + 1;
+    int y = get_global_id (1) + 1;
+    int width = get_global_size (0) + 2;
+
+    values[y * width + x] = 1;
+}
+
+kernel void
+grow_region_above_threshold (global float *input,
+                             global float *visited,
+                             global float *output,
+                             global int *counter,
+                             const float threshold)
+{
+    int x = get_global_id (0) + 1;
+    int y = get_global_id (1) + 1;
+    int width = get_global_size (0) + 2;
+    int offset = y * width;
+    int index = offset + x;
+    float value, diff = 0.0f, maximum = 0.0f;
+    int dxy;
+
+    if (visited[index]) {
+        return;
+    }
+    value = input[index];
+
+    for (dxy = -1; dxy < 2; dxy += 2) {
+        /* Check x +/- 1 */
+        if (visited[offset + x + dxy]) {
+            diff = fabs (value - input[offset + x + dxy]);
+            if (diff > maximum) {
+                maximum = diff;
+            }
+        }
+        /* Check y +/- 1 */
+        if (visited[(y + dxy) * width + x]) {
+            diff = fabs (value - input[(y + dxy) * width + x]);
+            if (diff > maximum) {
+                maximum = diff;
+            }
+        }
+    }
+    if (maximum > threshold) {
+        output[index] = 1;
+        atomic_inc (counter);
+    }
+}
+
+kernel void
+fill_holes (global int *input,
+            global int *visited,
+            global int *output,
+            global int *counter)
+{
+    int x = get_global_id (0) + 1;
+    int y = get_global_id (1) + 1;
+    int width = get_global_size (0) + 2;
+    int offset = y * width;
+    int index = offset + x;
+
+    if (!visited[index] || input[index]) {
+        return;
+    }
+
+    if (!(visited[offset + x - 1] && visited[offset + x + 1] && visited[(y - 1) * width + x] && visited[(y + 1) * width + x])) {
+        output[index] = 0;
+        atomic_inc (counter);
+    }
+}
+