After combining your IDF files and before extracting, you should generate a Bad Pixels Map (BPM) file for your combined file. This is done with bpm_combine. cf_bad_pixels, the pipeline BPM generator generates a BPM file for each exposure from its IDF file (and if present the associated housekeeping and jitter files), but cannot generate a BPM for an IDF file containing several exposures. bpm_combine will combine the BPM files in the same way idf_combine or CF_EDIT combine IDF files. It takes into account the possible alignment performed on the exposures with CF_EDIT.
The syntax for bpm_combine is:
bpm_combine M1010101all2attagfbpm.fit M1010101all2attagfidf.fit
The program uses the information in the main header of the combined IDF file to find which IDF files were used to make it. It then opens these IDF files to find the associated BPM files filenames. Last it opens the BPM files for each exposures and combines them. For this program to work, all the IDF files that were used to generate the combined IDF file as well as their associated BPM files must be in the current directory.