---
name: "mPix2Coord"
section: "1"
platform: "linux"
package: "montage"
version: "6.1+dfsg-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mPix2Coord"
---

# mPix2Coord(1)

Output the sky location corresponding to a pixel coordinate

## NAME

mPix2Coord - Output the sky location corresponding to a pixel coordinate

## SYNOPSIS

mPix2Coord \[-d\] template.hdr ixpix jypix

## DESCRIPTION

Takes an image FITS header template and a pixel (x,y) coordinate, and outputs the corresponding sky location. Newer mExamine can do the same and more for real image files.

## OPTIONS

- \-d

  Print out additional debugging information

## ARGUMENTS

- template.hdr

  ASCII header template describing the image (either a FITS image, or a JPEG file created from the FITS file)

- ixpix

  X coordinate (pixel location) on image

- jypix

  Y coordinate (pixel location) on image

## RESULT

**\[struct stat="OK", lon=***ra***, lat=***dec***\]**

*where ra, dec are the sky coordinates that correspond to the input pixel.*

## MESSAGES

- *OK*

  *\[struct stat="OK", lon=ra, lat=dec\]*

- *ERROR*

  *Bad template: template.hdr*

- *ERROR*

  *Output wcsinit() failed.*

## EXAMPLES

*To find out what the coordinates are at the 100,130 pixel on an image defined by* **template.hdr***:*

- *$ mPix2Coord template.hdr 100 130*

  *\[struct stat="OK", lon=0.027777, lat=0.036110\]*

## BUGS

*The drizzle algorithm has been implemented but has not been tested* *in this release.*

*If a header template contains carriage returns (i.e., created/modified* *on a Windows machine), the cfitsio library will be unable to read it* *properly, resulting in the error: \[struct stat="ERROR", status=207,* *msg="illegal character in keyword"\]*

*It is best for the background correction algorithms if the area* *described in the header template completely encloses all of the input* *images in their entirety. If parts of input images are "chopped off"* *by the header template, the background correction will be affected. We* *recommend you use an expanded header for the reprojection and* *background modeling steps, returning to the originally desired header* *size for the final coaddition. The default background matching assumes* *that there are no non-linear background variations in the individual* *images (and therefore in the overlap differences). If there is any* *uncertainty in this regard, it is safer to turn on the "level only"* *background matching (the "-l" flag in mBgModel.*

## COPYRIGHT

*2001-2015 California Institute of Technology, Pasadena, California*

*If your research uses Montage, please include the following* *acknowledgement: "This research made use of Montage. It is funded by* *the National Science Foundation under Grant Number ACI-1440620, and* *was previously funded by the National Aeronautics and Space* *Administration's Earth Science Technology Office, Computation* *Technologies Project, under Cooperative Agreement Number NCC5-626* *between NASA and the California Institute of Technology."*

*The Montage distribution includes an adaptation of the MOPEX algorithm* *developed at the Spitzer Science Center.*