An web tool for mixing and colorizing images from JWST's NIRCam infrared images. WebGL and the GPU is used to composite 6 readings from different infrared wavelengths and display the result.
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Images were downloaded from the Space Telescope Science Institute's (STScI) MAST portal in .fits format. 6 infrared frequency fits files were downloaded for each observation.
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PixInsight was used to isolate the correct layer of the fits file and crop the image. Star registration was used to align each image with respect to the others so they could be stacked. Then the images were transformed using the histogram tool to bring out details in a range that could be viewed on a computer monitor. These images were then exported as grayscale .tiff files and converted to grayscale .png to reduce the size and prepare them for use in a browser.
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Images were uploaded to an Amazon Web Services S3 bucket and cached globally using Cloudfront.
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When the https://jwst.fun web tool loads, it downloads each of the six .png images corresponding to each of the six infrared wavelengths imaged by the NIRCam instrument on JWST.
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These images are loaded as textures into a GLSL fragment shader for fast compositing on the GPU.
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Next, the levels of each grayscale texture are adjusted based on the user's settings for each filter in the web tools UI labeled "Levels."
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Next, the adjusted grayscale texture is colorized using the hue and saturation provided by the user settings for each filter.
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Finally, each layer is composited with the layer below it using the screen blend mode and the opacity provided by users' settings for each filter.
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The final color value of the last layer is used for that fragment of the image.
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Once each fragment is computed by the GPU, WebGL renders them to the viewport of the web tool.