Replicating sextractor command with sep.

[igorkolesnikov13]

Hi to everyone.

Guys, I'm really looking forward to being able to improve my code with sep.
I have the following command that I'm currently employing in my pipeline:
sextractor image.fit -BACK_SIZE 32 -DETECT_THRESH 0.8 -CATALOG_NAME image.cat -CHECKIMAGE_TYPE SEGMENTATION,BACKGROUND -CHECKIMAGE_NAME image_segmented.fits, image_background.fits -VERBOSE_TYPE QUIET

I already found the part of the Background image in the documentation, but the part of the Segmented image and .cat file (with several parameters) is not clear. Is this possible to achieve with sep?
Appreciate any help.

[kbarbary]

SEP breaks what sextractor does into several different functions:

• background subtraction: sep.Background
• object detection: sep.extract
• aperture photometry: sep.sum_circle, sep.sum_ellipse, etc.

The tutorial gives a good overview of how to piece these together.

Specifically, for some of the options you're using:

• -BACK_SIZE 32: This is an option in sep.Background
• DETECT_THRESH 0.8: This is an option in sep.extract. For example: sep.extract(data_sub, 0.8, err=bkg.globalrms)
• -CATALOG_NAME image.cat: This is not relevant because SEP doesn't deal with reading or writing files. Instead, some of this information is included in the structured numpy array returned by sep.extract.
• -CHECKIMAGE_TYPE SEGMENTATION,BACKGROUND -CHECKIMAGE_NAME image_segmented.fits, image_background.fits: The tutorial shows how to get a background image. The segmentation map can be returned with the segmentation_map=True argument to sep.extract.