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(requires Microsoft® Windows®)

This tutorial will demonstrate how to load an image into the GIMP and convert it to the CometScore™ format.

GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring. The terms of usage and rules about copying are clearly listed in the GNU General Public License. Click here for downloads.

 

  1. Launch the GIMP by double-clicking on the icon.

  1. Click File | Open to specify an image file to process.

  1. Select your image file and click OK.

  1. If your comets are oriented from right (head) to left (tail) then you'll have to rotate the image as the CometScore™ expects all heads on the left. This simple image rotation will not result in a loss of data. Right-click on the image and then click Image | Transforms | Rotate | 180 degrees. If your comets are oriented north-to-south or south-to-north, you can rotate 90 or 270 degrees to achieve the desired result.

  1. If your camera saves color images, you must convert to grayscale. Right-click on the image and then click Image | Mode | Grayscale. This operation will convert from color to black-and-white. It is important to note that this conversion will skew image intensity slightly depending on the color of the image data. For example, 'green' comets will have a slightly different intensity value than 'blue' comets when converted to grayscale as the most common conversion equation emphasizes green over red and red over blue. (gray = 0.299 * red + 0.587 * green + 0.114 * blue). However, it is equally important to note that every comet will be skewed exactly the same so all relative metrics will be unaffected. The optimum solution for single-wavelength image data is to put the camera in monochrome mode.

  1. If your camera saves image data in a format other than bitmap, you must convert to a standard bitmap. Right-click on the image and then click File | Save As.

  1. Select BMP from the file type list and click OK.

  1. GIMP will ask for options. Make sure that RLE encoded is off, which is the default. Click OK.

Your image data is now compatible with the CometScore™.