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From the full COSMOS catalog, we select appropriate Exp, Dev, and Sersic models according to the following standards:   1. Exp models: \(mag \le 23.0\), \(b/a \ge 0.4\), \(2.0 \le R_e \le 20.0\), and \(MADEXP\_DEV > 1.0\) 1.0\); This gives 9630 models in the catalog.  2. Dev models: \(mag \le 23.0\), \(b/a \ge 0.5\), \(2.0 \le R_e \le 20.0\), and \(MADEXP\_DEV \le 1.0\); This gives 6390 models in the catalog.  3. Sersic models: \(mag \le 23.0\), \(b/a \ge 0.4\), \(3.0 \le R_e \le 20.0\), and \(0.8 \le n_{Sersic} \le 4.0\); This gives 7523 models in the catalog.  The MADEXP\_DEV is the ratio of MAD (Median absolute deviation) of the Exp and Dev models. MADEXP\_DEV smaller than 1.0 indicates that the galaxy is more Exp-like; larger than 1.0 means it is more Dev-like. The cut at low axis ratio and low Sersic index is simply because GalSim sometimes fails to generate such model due to the maximum iterations allowed.  ## Fake Galaxies Injection   At this point, we only work on single frame images. A group of 22 "clean" images are selected from the visit=1236 COSMOS-UDEEP i-band data. We visually check the data for this test. These  images to ensure are from CCDs  thatthey  are close to the central region center  of the camera, and camera. And, we visually check the images to ensure that  the contamination from bright saturated stars is at minimum. For each run, 50 models are randomly selected from the input catalog, and are injected into these 22 images at the same, random locations. The calibration parameters and PSF models are extracted at the exact X-Y locations, and are passed to the funcation that generates the fake galaxy image. Appropriate noise is also added to the models before we put them on the images. We make sure the random image coordinates are not too close to the edge, but do not put special effort into avoiding real objects on the images. The X-Y coordinates of these fake galaxies, along with their ID, are recorded in the header of the images.   After that, the fake-injected images are passed to the pipeline for source detection and photometric measurements. We cross-match the X-Y coordinates of the fake objects with the ones estimated by the pipeline using a 2 pixel maximun separation. For the ones return a multiple-match, we keep the one with the smallest separation (Claire has tried a different approach, which is keep all the matched objects. It has very small impact on the results). Meanwhile, we also keep record of the ones without any matched objects.  To make sure that the input models reflect the intrinsic distributions of key parameters of the COSMOS galaxy models, we repeat this process 9 times. The same model can be selected in different runs, but it is very rare cases. In general, we have 420-440 different models for Exp, Dev, and Sersic cases. For each model, the average, median, and standard deviation of important photometric parameters are estimated from all the detections (for most cases >10 out of 22), and are used to compared with the input values.