STScI Logo

isoreg xray.xspatial


NAME · USAGE · DESCRIPTION · PARAMETERS · EXAMPLES · TIME_REQUIREMENTS
BUGS · SEE_ALSO

NAME

isoreg -- create a mask file by applying intensity levels to image data

USAGE

isoreg in_image out_mask levels

DESCRIPTION

ISOREG applies intensity levels to an image and creates an output mask file with intensity regions. A mapping between the intensity levels and mask region ids are displayed. Intensity levels such as the contour levels determined in task Imcontour/Tvimcontour are a good application for this task. The contour levels (i.e. 6.4860,9.8309,14.9009,22.5855, 34.2333,51.8880) are mapped to mask regions (i.e. 1,2,3,4,5,6) and saved in the output pl file.

PARAMETERS

in_image = "" prompt = Input image filename

Name of the input image file to be read.

out_mask = "" prompt = Output Isoregions mask file [root_iso.pl]

Name of output pl mask file to be written.

levels = "" prompt = Intensity Levels

List of intensity levels.

(clobber = no) [boolean]

Boolean flag specifying whether or not the output Table file can be overwritten, if it already exists.

(display = 2) [int]

Display info to screen. Integer of range 0-5. The higher the number the more verbose the display.

EXAMPLES

1. Apply intensity levels to an image.

        xs> isoreg myimage.imh mymask.pl "2 4 8 16 32"

        Mask Id / Intensity Level Pairs:
        --------------------------------
           1       2.000
           2       4.000
           3       8.000
           4       16.000
           5       32.000

        Writing to Output file:  mymask.pl

2. Apply intensity contour levels to a smoothed image file. First run imcontour, followed by isoreg, and finally sum the counts in each region with imcnts.

        xp> imcontour
        IRAF image filename (snr_smo.imh):
        Grid type (sky|pixel) (sky):
        Contour Units (pixel|peak|sigma) (peak):
        Contour Levels (log 10 80 5):

        Input Image Size is 128 x 128 Pixels

        Determined Contour Levels:
        (6.4860,9.8309,14.9009,22.5855,34.2333,51.8880)

        Plot Device is stdgraph & Scale Device is stdplot

        xs> isoreg
        Input image filename : snr_smo.imh
        Output Isoregions mask file [root_iso.pl]: .
        Intensity Levels: 6.4860,9.8309,14.9009,22.5855,34.2333,51.8880

        Mask Id / Intensity Level Pairs:
        --------------------------------
           1       6.486
           2       9.831
           3       14.901
           4       22.586
           5       34.233
           6       51.888

        Writing to Output file:  ./snr_iso.pl

        xs> imcnts
        source image file : snr_smo.imh
        source region descriptor : snr_iso.pl
        background image file or cts/pixel (0):
        root name for output file [root_cnt.tab] (.):

        SOURCE/nimage:          snr_smo.imh
        mask_name:      in memory
        mask_type:      region
        ref_file:       none
        xdim:           128
        ydim:           128
        scale:          none
        regions:        FIELD
        no exposure correction

        constant bkgd:  0.0000 counts/sq. pixel

        user normalization: 1.00
        time normalization: 1.00
        final normalization: 1.00

        SOURCE DATA:
        REGION          COUNTS          PIXELS
        1               8047            1038
        2               3107            265
        3               1263            73
        4               1043            37
        5               1367            32
        6               940             16

        BKGD-SUBTRACTED DATA:
        REG   COUNTS     ERROR      BKGD       PIXELS   CNT/PIX    ERR/PIX
        1     8047.23    89.7063    0.00       1038     7.7526     0.0864
        2     3107.55    55.7454    0.00       265      11.7266    0.2104
        3     1263.64    35.5477    0.00       73       17.3101    0.4870
        4     1043.23    32.2991    0.00       37       28.1954    0.8729
        5     1367.82    36.9841    0.00       32       42.7444    1.1558
        6     940.46     30.6669    0.00       16       58.7786    1.9167
        Creating table output file: ./snr_cnt.tab

TIME REQUIREMENTS

BUGS

Isoreg does not work on and image with a section (i.e. foo.imh[1:100,1:100]). Use task imcopy to copy the image with the section into a new image before running Isoreg.

SEE ALSO

Documentation on imcontour (help imcontour ) for a description of contouring an IRAF image/qpoe file.

Documentation on tvimcontour (help tvimcontour ) for a description of contouring an IRAF image/qpoe file to an imtool window.

Documentation on imcnts (help imcnts ) for a description of getting counts from mask regions.


Source Code · Search Form · STSDAS