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true-color → true color

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heyarne 2021-03-16 21:15:07 +01:00
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sources/01b-visualization.ipynb
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@ -6,11 +6,11 @@
"source": [
"# Interpretation and Visualization\n",
"\n",
"This notebook shows how to access the content of the products downloaded in [](01a-download-process.ipynb) and plot a true-color rendering. \n",
"While the products already contain a True-Color Image (TCI), this approach is useful for two reasons:\n",
"This notebook shows how to access the content of the products downloaded in [](01a-download-process.ipynb) and plot a true color rendering. \n",
"While the products already contain a True Color Image (TCI), this approach is useful for two reasons:\n",
"\n",
"1. It allows comparing the custom rendering with a rendering provided by official sources, thereby providing a template that can be used to spot any errors.\n",
"2. Generating a custom True-Color Image can be useful for further image manipulations, changing contrast or changing out single bands for others to highlight phenomena which are more visible at certain wavelengths.\n",
"2. Generating a custom True Color Image can be useful for further image manipulations, changing contrast or changing out single bands for others to highlight phenomena which are more visible at certain wavelengths.\n",
"\n",
"First the shape of Berlin is created from data previously downloaded from OpenStreetMap:"
]
@ -110,7 +110,7 @@
"\n",
"The largest share of the product size is made up by `*.jp2` files, which are raster images which contain geocoded spectral band information at a fixed resolution.\n",
"Data on each spectral band captured by the Sentinel-2 mission is distributed on a per-file basis, which is why most of these files contain data on a single channel only.\n",
"An exception is the included True-Color Image, which contains data in red, green and blue channels.\n",
"An exception is the included True Color Image, which contains data in red, green and blue channels.\n",
"There is a function that, given a resolution and one or more spectral band name, returns the correct file paths.\n",
"It contains code to deal with compressed or uncompressed products."
]
@ -178,7 +178,7 @@
"source": [
"Using the compressed zip-file, while slightly inconvenient, makes sense because it allows saving disk space and avoiding the extra step of decompressing every single downloaded product.\n",
"\n",
"The pre-rendered True-Color Image can be plotted for an impression of the product's contents:"
"The pre-rendered True Color Image can be plotted for an impression of the product's contents:"
]
},
{
@ -250,9 +250,9 @@
"\n",
"It is used to open one or more data sets at a time and close them as soon as the execution pointer of the block has ended. This means data is only read inside the block, which is also where the processing usually takes place.\n",
"\n",
"## Creating a Custom True-Color Composition\n",
"## Creating a Custom True Color Composition\n",
"\n",
"While for many use cases using the TCI can be enough, knowing how to compose True-Color Images provides additional merit as explained above.\n",
"While for many use cases using the TCI can be enough, knowing how to compose True Color Images provides additional merit as explained above.\n",
"\n",
"The blue, green, and red parts of the spectrum are represented in the raster files for the bands 2, 3 and 4 respectively\n",
"`sentinel_helpers.py` contains a function wrapping `scihub_band_paths` to retrieve those bands in a resolution of choice:"
@ -488,7 +488,7 @@
"\n",
"with r.open(b02) as blue, r.open(b03) as green, r.open(b04) as red, r.open(low_res_tci) as tci:\n",
" fig, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize=(18,6))\n",
" fig.suptitle('True-Color Image', fontsize=20)\n",
" fig.suptitle('True Color Image', fontsize=20)\n",
" \n",
" ax1.grid(False)\n",
" ax2.grid(False)\n",