1 files changed, 98 insertions, 0 deletions
diff --git a/src/fes/cf_fes_apply_bias.c b/src/fes/cf_fes_apply_bias.c
new file mode 100644
index 0000000..7591757
--- /dev/null
+++ b/src/fes/cf_fes_apply_bias.c
@@ -0,0 +1,98 @@
+/*******************************************************************************
+ *	      Johns Hopkins University
+ *	      Center For Astrophysical Sciences
+ *	      FUSE
+ *******************************************************************************
+ *
+ * Synopsis: cf_apply_fes_bias(fitsfile *fesfits, float **image, 
+ *                                       float *bias, int axis1, int axis2)
+ *
+ * Description: Apply FES bias in *bias to the raw FES image in **image
+ *     To apply the bias, I simply loop through the 
+ *     bias image pixel by pixel and subtract that 
+ *     value from the given FES image.
+ *
+ * Arguments:	fitsfile *fesfits       fits file for image so that we can add
+ *                                      history/comment lines to the HDU
+ *              float   **image 	FES image
+ *              float   *bias	 	FES bias image
+ *              int     axis1, axis2    size of each axis of the images.
+ *                                      This presumes that both images are 
+ *                                      the same size when they get here.
+ *
+ * Returns:	0 upon successful completion
+ *
+ * History:	07/08/98	gak     calfes_design.070898 design documented
+ *              07/22/98        mlr     started work
+ *              04/06/99        mlr     Broke this actual subroutine out
+ *                                      from cf_fes_bias.c
+ *              08/10/99        mlr     added fesfits to the argument list
+ *              04/25/02        wvd	initialize status to zero
+ *
+ ******************************************************************************/
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "calfuse.h"
+#include "cf_calfes.h"
+
+#define CF_PRGM_ID      "cf_fes_apply_bias"
+#define CF_VER_NUM      "1.4"
+
+int cf_fes_apply_bias(fitsfile *fesfits, float **image,  
+                               float *bias, int naxis1, int naxis2)
+{
+        int i, j;  /*loop counters */
+        int status=0;
+        float os_bias, os_data;
+        float factor;
+        char buffer[80];
+
+        cf_timestamp(CF_PRGM_ID,CF_VER_NUM, "Applying FES bias");
+        
+        os_bias=0.;
+        os_data=0.;
+
+	if (naxis1 == 520)  /* 1x1 binning */
+   	{
+           for (j=0; j<520; j++)
+	      for (i=512; i<520; i++)
+              {
+	         os_bias += bias[j*naxis1+i];
+	         os_data += (*image)[j*naxis1+1];
+              }
+        }
+        else if (naxis1 == 260)  /* 2x2 binning */
+        {
+           for (j=0; j<260; j++)
+               for (i=256; i<260; i++)
+               {
+	         os_bias += bias[j*naxis1+i];
+	         os_data += (*image)[j*naxis1+1];
+               }
+        }
+        else   /*bail out -- unsupported image size or binning */
+            exit(-1);
+
+      factor = os_data / os_bias;
+      sprintf(buffer, "FES BIAS FACTOR = %lf",factor);
+      cf_timestamp(CF_PRGM_ID, CF_VER_NUM, buffer);
+
+/*      FITS_write_history(fesfits, buffer, &status); */
+
+      for (j=0; j<naxis2; j++)
+         for (i=0; i<naxis1; i++)
+         {
+/*     printf("pixel[%d, %d] = %lf\n",i,j, (*image)[j*naxis1+i]); */
+                    if ( (*image)[j*naxis1+i] != FES_BAD_PIX )
+                          (*image)[j*naxis1+i] -= bias[j*naxis1+i] * factor;
+                    else
+                        printf("bad pixel[%d, %d]\n",i,j);
+          }
+
+      cf_timestamp(CF_PRGM_ID, CF_VER_NUM, "Finished FES bias");
+
+      return(status);
+
+}