... Meta Index / Home Page / Grism chain procedure . The task omdetect runs on the image with spectra aligned to the pixel columns of the image, i.e. the output of omgprep . It creates a list of detected sources, which becomes the input for the task omgrism . Practically all the sources detected by omdetect in the grism images are classified as extended. ... An example of an image (visual-grism) with the sources detected by omdetect is shown in Fig. ...