Index: /trunk/psModules/src/imcombine/pmSubtractionKernels.c
===================================================================
--- /trunk/psModules/src/imcombine/pmSubtractionKernels.c	(revision 14520)
+++ /trunk/psModules/src/imcombine/pmSubtractionKernels.c	(revision 14521)
@@ -4,4 +4,5 @@
 
 #include <stdio.h>
+#include <string.h>
 #include <pslib.h>
 
@@ -628,2 +629,28 @@
     }
 }
+
+
+pmSubtractionKernelsType pmSubtractionKernelsTypeFromString(const char *type)
+{
+    if (strcasecmp(type, "POIS") == 0) {
+        return PM_SUBTRACTION_KERNEL_POIS;
+    }
+    if (strcasecmp(type, "ISIS") == 0) {
+        return PM_SUBTRACTION_KERNEL_ISIS;
+    }
+    if (strcasecmp(type, "SPAM") == 0) {
+        return PM_SUBTRACTION_KERNEL_SPAM;
+    }
+    if (strcasecmp(type, "FRIES") == 0) {
+        return PM_SUBTRACTION_KERNEL_FRIES;
+    }
+    if (strcasecmp(type, "GUNK") == 0) {
+        return PM_SUBTRACTION_KERNEL_GUNK;
+    }
+    if (strcasecmp(type, "RINGS") == 0) {
+        return PM_SUBTRACTION_KERNEL_RINGS;
+    }
+
+    psError(PS_ERR_BAD_PARAMETER_VALUE, true, "Unrecognised kernel type: %s", type);
+    return PM_SUBTRACTION_KERNEL_NONE;
+}
Index: /trunk/psModules/src/imcombine/pmSubtractionKernels.h
===================================================================
--- /trunk/psModules/src/imcombine/pmSubtractionKernels.h	(revision 14520)
+++ /trunk/psModules/src/imcombine/pmSubtractionKernels.h	(revision 14521)
@@ -6,4 +6,5 @@
 /// Type of subtraction kernel
 typedef enum {
+    PM_SUBTRACTION_KERNEL_NONE,         ///< Nothing --- an error
     PM_SUBTRACTION_KERNEL_POIS,         ///< Pan-STARRS Optimal Image Subtraction --- delta functions
     PM_SUBTRACTION_KERNEL_ISIS,         ///< Traditional kernel --- gaussians modified by polynomials
@@ -91,3 +92,8 @@
     );
 
+/// Return the appropriate type from a string
+pmSubtractionKernelsType pmSubtractionKernelsTypeFromString(const char *string // String name for kernel type
+    );
+
+
 #endif