diff --git a/.gitignore b/.gitignore
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,145 @@
+
+# Created by https://www.toptal.com/developers/gitignore/api/python
+# Edit at https://www.toptal.com/developers/gitignore?templates=python
+
+### Python ###
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# End of https://www.toptal.com/developers/gitignore/api/python
diff --git a/LE07_L1TP_177025_20210723_20210818_02_T1_B1.TIF b/LE07_L1TP_177025_20210723_20210818_02_T1_B1.TIF
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diff --git a/LE07_L1TP_177025_20210723_20210818_02_T1_MTL.txt b/LE07_L1TP_177025_20210723_20210818_02_T1_MTL.txt
new file mode 100644
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--- /dev/null
+++ b/LE07_L1TP_177025_20210723_20210818_02_T1_MTL.txt
@@ -0,0 +1,300 @@
+GROUP = LANDSAT_METADATA_FILE
+  GROUP = PRODUCT_CONTENTS
+    ORIGIN = "Image courtesy of the U.S. Geological Survey"
+    DIGITAL_OBJECT_IDENTIFIER = "https://doi.org/10.5066/P9TU80IG"
+    LANDSAT_PRODUCT_ID = "LE07_L1TP_177025_20210723_20210818_02_T1"
+    PROCESSING_LEVEL = "L1TP"
+    COLLECTION_NUMBER = 02
+    COLLECTION_CATEGORY = "T1"
+    OUTPUT_FORMAT = "GEOTIFF"
+    FILE_NAME_BAND_1 = "LE07_L1TP_177025_20210723_20210818_02_T1_B1.TIF"
+    FILE_NAME_BAND_2 = "LE07_L1TP_177025_20210723_20210818_02_T1_B2.TIF"
+    FILE_NAME_BAND_3 = "LE07_L1TP_177025_20210723_20210818_02_T1_B3.TIF"
+    FILE_NAME_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_B4.TIF"
+    FILE_NAME_BAND_5 = "LE07_L1TP_177025_20210723_20210818_02_T1_B5.TIF"
+    FILE_NAME_BAND_6_VCID_1 = "LE07_L1TP_177025_20210723_20210818_02_T1_B6_VCID_1.TIF"
+    FILE_NAME_BAND_6_VCID_2 = "LE07_L1TP_177025_20210723_20210818_02_T1_B6_VCID_2.TIF"
+    FILE_NAME_BAND_7 = "LE07_L1TP_177025_20210723_20210818_02_T1_B7.TIF"
+    FILE_NAME_BAND_8 = "LE07_L1TP_177025_20210723_20210818_02_T1_B8.TIF"
+    FILE_NAME_QUALITY_L1_PIXEL = "LE07_L1TP_177025_20210723_20210818_02_T1_QA_PIXEL.TIF"
+    FILE_NAME_QUALITY_L1_RADIOMETRIC_SATURATION = "LE07_L1TP_177025_20210723_20210818_02_T1_QA_RADSAT.TIF"
+    FILE_NAME_GROUND_CONTROL_POINT = "LE07_L1TP_177025_20210723_20210818_02_T1_GCP.txt"
+    FILE_NAME_ANGLE_COEFFICIENT = "LE07_L1TP_177025_20210723_20210818_02_T1_ANG.txt"
+    FILE_NAME_ANGLE_SENSOR_AZIMUTH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_VAA.TIF"
+    FILE_NAME_ANGLE_SENSOR_ZENITH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_VZA.TIF"
+    FILE_NAME_ANGLE_SOLAR_AZIMUTH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_SAA.TIF"
+    FILE_NAME_ANGLE_SOLAR_ZENITH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_SZA.TIF"
+    FILE_NAME_METADATA_ODL = "LE07_L1TP_177025_20210723_20210818_02_T1_MTL.txt"
+    FILE_NAME_METADATA_XML = "LE07_L1TP_177025_20210723_20210818_02_T1_MTL.xml"
+    DATA_TYPE_BAND_1 = "UINT8"
+    DATA_TYPE_BAND_2 = "UINT8"
+    DATA_TYPE_BAND_3 = "UINT8"
+    DATA_TYPE_BAND_4 = "UINT8"
+    DATA_TYPE_BAND_5 = "UINT8"
+    DATA_TYPE_BAND_6_VCID_1 = "UINT8"
+    DATA_TYPE_BAND_6_VCID_2 = "UINT8"
+    DATA_TYPE_BAND_7 = "UINT8"
+    DATA_TYPE_BAND_8 = "UINT8"
+    DATA_TYPE_QUALITY_L1_PIXEL = "UINT16"
+    DATA_TYPE_QUALITY_L1_RADIOMETRIC_SATURATION = "UINT16"
+    DATA_TYPE_ANGLE_SENSOR_AZIMUTH_BAND_4 = "INT16"
+    DATA_TYPE_ANGLE_SENSOR_ZENITH_BAND_4 = "INT16"
+    DATA_TYPE_ANGLE_SOLAR_AZIMUTH_BAND_4 = "INT16"
+    DATA_TYPE_ANGLE_SOLAR_ZENITH_BAND_4 = "INT16"
+  END_GROUP = PRODUCT_CONTENTS
+  GROUP = IMAGE_ATTRIBUTES
+    SPACECRAFT_ID = "LANDSAT_7"
+    SENSOR_ID = "ETM"
+    WRS_TYPE = 2
+    WRS_PATH = 177
+    WRS_ROW = 025
+    DATE_ACQUIRED = 2021-07-23
+    SCENE_CENTER_TIME = "07:26:38.9955869Z"
+    STATION_ID = "NSG"
+    CLOUD_COVER = 0.00
+    CLOUD_COVER_LAND = 0.00
+    IMAGE_QUALITY = 9
+    SATURATION_BAND_1 = "Y"
+    SATURATION_BAND_2 = "Y"
+    SATURATION_BAND_3 = "Y"
+    SATURATION_BAND_4 = "Y"
+    SATURATION_BAND_5 = "Y"
+    SATURATION_BAND_6_VCID_1 = "N"
+    SATURATION_BAND_6_VCID_2 = "N"
+    SATURATION_BAND_7 = "Y"
+    SATURATION_BAND_8 = "N"
+    SUN_AZIMUTH = 126.84545120
+    SUN_ELEVATION = 49.90781811
+    EARTH_SUN_DISTANCE = 1.0159141
+    SENSOR_MODE = "BUMPER"
+    SENSOR_MODE_SLC = "OFF"
+    SENSOR_ANOMALIES = "NONE"
+  END_GROUP = IMAGE_ATTRIBUTES
+  GROUP = PROJECTION_ATTRIBUTES
+    MAP_PROJECTION = "UTM"
+    DATUM = "WGS84"
+    ELLIPSOID = "WGS84"
+    UTM_ZONE = 37
+    GRID_CELL_SIZE_PANCHROMATIC = 15.00
+    GRID_CELL_SIZE_REFLECTIVE = 30.00
+    GRID_CELL_SIZE_THERMAL = 30.00
+    PANCHROMATIC_LINES = 15081
+    PANCHROMATIC_SAMPLES = 16981
+    REFLECTIVE_LINES = 7541
+    REFLECTIVE_SAMPLES = 8491
+    THERMAL_LINES = 7541
+    THERMAL_SAMPLES = 8491
+    ORIENTATION = "NORTH_UP"
+    CORNER_UL_LAT_PRODUCT = 51.28241
+    CORNER_UL_LON_PRODUCT = 34.82816
+    CORNER_UR_LAT_PRODUCT = 51.35561
+    CORNER_UR_LON_PRODUCT = 38.48012
+    CORNER_LL_LAT_PRODUCT = 49.25322
+    CORNER_LL_LON_PRODUCT = 35.00205
+    CORNER_LR_LAT_PRODUCT = 49.32136
+    CORNER_LR_LON_PRODUCT = 38.50186
+    CORNER_UL_PROJECTION_X_PRODUCT = 209100.000
+    CORNER_UL_PROJECTION_Y_PRODUCT = 5689500.000
+    CORNER_UR_PROJECTION_X_PRODUCT = 463800.000
+    CORNER_UR_PROJECTION_Y_PRODUCT = 5689500.000
+    CORNER_LL_PROJECTION_X_PRODUCT = 209100.000
+    CORNER_LL_PROJECTION_Y_PRODUCT = 5463300.000
+    CORNER_LR_PROJECTION_X_PRODUCT = 463800.000
+    CORNER_LR_PROJECTION_Y_PRODUCT = 5463300.000
+  END_GROUP = PROJECTION_ATTRIBUTES
+  GROUP = LEVEL1_PROCESSING_RECORD
+    ORIGIN = "Image courtesy of the U.S. Geological Survey"
+    DIGITAL_OBJECT_IDENTIFIER = "https://doi.org/10.5066/P9TU80IG"
+    REQUEST_ID = "P700y95yl7543_00333"
+    LANDSAT_SCENE_ID = "LE71770252021204NSG00"
+    LANDSAT_PRODUCT_ID = "LE07_L1TP_177025_20210723_20210818_02_T1"
+    PROCESSING_LEVEL = "L1TP"
+    COLLECTION_CATEGORY = "T1"
+    OUTPUT_FORMAT = "GEOTIFF"
+    DATE_PRODUCT_GENERATED = 2021-08-18T17:58:16Z
+    PROCESSING_SOFTWARE_VERSION = "LPGS_15.5.0"
+    FILE_NAME_BAND_1 = "LE07_L1TP_177025_20210723_20210818_02_T1_B1.TIF"
+    FILE_NAME_BAND_2 = "LE07_L1TP_177025_20210723_20210818_02_T1_B2.TIF"
+    FILE_NAME_BAND_3 = "LE07_L1TP_177025_20210723_20210818_02_T1_B3.TIF"
+    FILE_NAME_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_B4.TIF"
+    FILE_NAME_BAND_5 = "LE07_L1TP_177025_20210723_20210818_02_T1_B5.TIF"
+    FILE_NAME_BAND_6_VCID_1 = "LE07_L1TP_177025_20210723_20210818_02_T1_B6_VCID_1.TIF"
+    FILE_NAME_BAND_6_VCID_2 = "LE07_L1TP_177025_20210723_20210818_02_T1_B6_VCID_2.TIF"
+    FILE_NAME_BAND_7 = "LE07_L1TP_177025_20210723_20210818_02_T1_B7.TIF"
+    FILE_NAME_BAND_8 = "LE07_L1TP_177025_20210723_20210818_02_T1_B8.TIF"
+    FILE_NAME_QUALITY_L1_PIXEL = "LE07_L1TP_177025_20210723_20210818_02_T1_QA_PIXEL.TIF"
+    FILE_NAME_QUALITY_L1_RADIOMETRIC_SATURATION = "LE07_L1TP_177025_20210723_20210818_02_T1_QA_RADSAT.TIF"
+    FILE_NAME_GROUND_CONTROL_POINT = "LE07_L1TP_177025_20210723_20210818_02_T1_GCP.txt"
+    FILE_NAME_ANGLE_COEFFICIENT = "LE07_L1TP_177025_20210723_20210818_02_T1_ANG.txt"
+    FILE_NAME_ANGLE_SENSOR_AZIMUTH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_VAA.TIF"
+    FILE_NAME_ANGLE_SENSOR_ZENITH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_VZA.TIF"
+    FILE_NAME_ANGLE_SOLAR_AZIMUTH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_SAA.TIF"
+    FILE_NAME_ANGLE_SOLAR_ZENITH_BAND_4 = "LE07_L1TP_177025_20210723_20210818_02_T1_SZA.TIF"
+    FILE_NAME_METADATA_ODL = "LE07_L1TP_177025_20210723_20210818_02_T1_MTL.txt"
+    FILE_NAME_METADATA_XML = "LE07_L1TP_177025_20210723_20210818_02_T1_MTL.xml"
+    FILE_NAME_CPF = "LE07CPF_20210701_20210930_02.03"
+    DATA_SOURCE_ELEVATION = "GLS2000"
+    GROUND_CONTROL_POINTS_VERSION = 5
+    GROUND_CONTROL_POINTS_MODEL = 1102
+    GEOMETRIC_RMSE_MODEL = 4.495
+    GEOMETRIC_RMSE_MODEL_Y = 3.328
+    GEOMETRIC_RMSE_MODEL_X = 3.022
+    EPHEMERIS_TYPE = "DEFINITIVE"
+  END_GROUP = LEVEL1_PROCESSING_RECORD
+  GROUP = LEVEL1_MIN_MAX_RADIANCE
+    RADIANCE_MAXIMUM_BAND_1 = 293.700
+    RADIANCE_MINIMUM_BAND_1 = -6.200
+    RADIANCE_MAXIMUM_BAND_2 = 300.900
+    RADIANCE_MINIMUM_BAND_2 = -6.400
+    RADIANCE_MAXIMUM_BAND_3 = 234.400
+    RADIANCE_MINIMUM_BAND_3 = -5.000
+    RADIANCE_MAXIMUM_BAND_4 = 241.100
+    RADIANCE_MINIMUM_BAND_4 = -5.100
+    RADIANCE_MAXIMUM_BAND_5 = 47.570
+    RADIANCE_MINIMUM_BAND_5 = -1.000
+    RADIANCE_MAXIMUM_BAND_6_VCID_1 = 17.040
+    RADIANCE_MINIMUM_BAND_6_VCID_1 = 0.000
+    RADIANCE_MAXIMUM_BAND_6_VCID_2 = 12.650
+    RADIANCE_MINIMUM_BAND_6_VCID_2 = 3.200
+    RADIANCE_MAXIMUM_BAND_7 = 16.540
+    RADIANCE_MINIMUM_BAND_7 = -0.350
+    RADIANCE_MAXIMUM_BAND_8 = 243.100
+    RADIANCE_MINIMUM_BAND_8 = -4.700
+  END_GROUP = LEVEL1_MIN_MAX_RADIANCE
+  GROUP = LEVEL1_MIN_MAX_REFLECTANCE
+    REFLECTANCE_MAXIMUM_BAND_1 = 0.467724
+    REFLECTANCE_MINIMUM_BAND_1 = -0.009874
+    REFLECTANCE_MAXIMUM_BAND_2 = 0.525664
+    REFLECTANCE_MINIMUM_BAND_2 = -0.011181
+    REFLECTANCE_MAXIMUM_BAND_3 = 0.498370
+    REFLECTANCE_MINIMUM_BAND_3 = -0.010631
+    REFLECTANCE_MAXIMUM_BAND_4 = 0.729914
+    REFLECTANCE_MINIMUM_BAND_4 = -0.015440
+    REFLECTANCE_MAXIMUM_BAND_5 = 0.696029
+    REFLECTANCE_MINIMUM_BAND_5 = -0.014632
+    REFLECTANCE_MAXIMUM_BAND_7 = 0.659156
+    REFLECTANCE_MINIMUM_BAND_7 = -0.013948
+    REFLECTANCE_MAXIMUM_BAND_8 = 0.597591
+    REFLECTANCE_MINIMUM_BAND_8 = -0.011554
+  END_GROUP = LEVEL1_MIN_MAX_REFLECTANCE
+  GROUP = LEVEL1_MIN_MAX_PIXEL_VALUE
+    QUANTIZE_CAL_MAX_BAND_1 = 255
+    QUANTIZE_CAL_MIN_BAND_1 = 1
+    QUANTIZE_CAL_MAX_BAND_2 = 255
+    QUANTIZE_CAL_MIN_BAND_2 = 1
+    QUANTIZE_CAL_MAX_BAND_3 = 255
+    QUANTIZE_CAL_MIN_BAND_3 = 1
+    QUANTIZE_CAL_MAX_BAND_4 = 255
+    QUANTIZE_CAL_MIN_BAND_4 = 1
+    QUANTIZE_CAL_MAX_BAND_5 = 255
+    QUANTIZE_CAL_MIN_BAND_5 = 1
+    QUANTIZE_CAL_MAX_BAND_6_VCID_1 = 255
+    QUANTIZE_CAL_MIN_BAND_6_VCID_1 = 1
+    QUANTIZE_CAL_MAX_BAND_6_VCID_2 = 255
+    QUANTIZE_CAL_MIN_BAND_6_VCID_2 = 1
+    QUANTIZE_CAL_MAX_BAND_7 = 255
+    QUANTIZE_CAL_MIN_BAND_7 = 1
+    QUANTIZE_CAL_MAX_BAND_8 = 255
+    QUANTIZE_CAL_MIN_BAND_8 = 1
+  END_GROUP = LEVEL1_MIN_MAX_PIXEL_VALUE
+  GROUP = LEVEL1_RADIOMETRIC_RESCALING
+    RADIANCE_MULT_BAND_1 = 1.1807E+00
+    RADIANCE_MULT_BAND_2 = 1.2098E+00
+    RADIANCE_MULT_BAND_3 = 9.4252E-01
+    RADIANCE_MULT_BAND_4 = 9.6929E-01
+    RADIANCE_MULT_BAND_5 = 1.9122E-01
+    RADIANCE_MULT_BAND_6_VCID_1 = 6.7087E-02
+    RADIANCE_MULT_BAND_6_VCID_2 = 3.7205E-02
+    RADIANCE_MULT_BAND_7 = 6.6496E-02
+    RADIANCE_MULT_BAND_8 = 9.7559E-01
+    RADIANCE_ADD_BAND_1 = -7.38071
+    RADIANCE_ADD_BAND_2 = -7.60984
+    RADIANCE_ADD_BAND_3 = -5.94252
+    RADIANCE_ADD_BAND_4 = -6.06929
+    RADIANCE_ADD_BAND_5 = -1.19122
+    RADIANCE_ADD_BAND_6_VCID_1 = -0.06709
+    RADIANCE_ADD_BAND_6_VCID_2 = 3.16280
+    RADIANCE_ADD_BAND_7 = -0.41650
+    RADIANCE_ADD_BAND_8 = -5.67559
+    REFLECTANCE_MULT_BAND_1 = 1.8803E-03
+    REFLECTANCE_MULT_BAND_2 = 2.1136E-03
+    REFLECTANCE_MULT_BAND_3 = 2.0039E-03
+    REFLECTANCE_MULT_BAND_4 = 2.9345E-03
+    REFLECTANCE_MULT_BAND_5 = 2.7979E-03
+    REFLECTANCE_MULT_BAND_7 = 2.6500E-03
+    REFLECTANCE_MULT_BAND_8 = 2.3982E-03
+    REFLECTANCE_ADD_BAND_1 = -0.011754
+    REFLECTANCE_ADD_BAND_2 = -0.013294
+    REFLECTANCE_ADD_BAND_3 = -0.012635
+    REFLECTANCE_ADD_BAND_4 = -0.018374
+    REFLECTANCE_ADD_BAND_5 = -0.017430
+    REFLECTANCE_ADD_BAND_7 = -0.016598
+    REFLECTANCE_ADD_BAND_8 = -0.013952
+  END_GROUP = LEVEL1_RADIOMETRIC_RESCALING
+  GROUP = LEVEL1_THERMAL_CONSTANTS
+    K1_CONSTANT_BAND_6_VCID_1 = 666.09
+    K2_CONSTANT_BAND_6_VCID_1 = 1282.71
+    K1_CONSTANT_BAND_6_VCID_2 = 666.09
+    K2_CONSTANT_BAND_6_VCID_2 = 1282.71
+  END_GROUP = LEVEL1_THERMAL_CONSTANTS
+  GROUP = LEVEL1_PROJECTION_PARAMETERS
+    MAP_PROJECTION = "UTM"
+    DATUM = "WGS84"
+    ELLIPSOID = "WGS84"
+    UTM_ZONE = 37
+    GRID_CELL_SIZE_PANCHROMATIC = 15.00
+    GRID_CELL_SIZE_REFLECTIVE = 30.00
+    GRID_CELL_SIZE_THERMAL = 30.00
+    ORIENTATION = "NORTH_UP"
+    RESAMPLING_OPTION = "CUBIC_CONVOLUTION"
+    SCAN_GAP_INTERPOLATION = 2.0
+  END_GROUP = LEVEL1_PROJECTION_PARAMETERS
+  GROUP = PRODUCT_PARAMETERS
+    CORRECTION_GAIN_BAND_1 = "CPF"
+    CORRECTION_GAIN_BAND_2 = "CPF"
+    CORRECTION_GAIN_BAND_3 = "CPF"
+    CORRECTION_GAIN_BAND_4 = "CPF"
+    CORRECTION_GAIN_BAND_5 = "CPF"
+    CORRECTION_GAIN_BAND_6_VCID_1 = "CPF"
+    CORRECTION_GAIN_BAND_6_VCID_2 = "CPF"
+    CORRECTION_GAIN_BAND_7 = "CPF"
+    CORRECTION_GAIN_BAND_8 = "CPF"
+    CORRECTION_BIAS_BAND_1 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_2 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_3 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_4 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_5 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_6_VCID_1 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_6_VCID_2 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_7 = "INTERNAL_CALIBRATION"
+    CORRECTION_BIAS_BAND_8 = "INTERNAL_CALIBRATION"
+    GAIN_BAND_1 = "L"
+    GAIN_BAND_2 = "L"
+    GAIN_BAND_3 = "L"
+    GAIN_BAND_4 = "L"
+    GAIN_BAND_5 = "L"
+    GAIN_BAND_6_VCID_1 = "L"
+    GAIN_BAND_6_VCID_2 = "H"
+    GAIN_BAND_7 = "L"
+    GAIN_BAND_8 = "L"
+    GAIN_CHANGE_BAND_1 = "LL"
+    GAIN_CHANGE_BAND_2 = "LL"
+    GAIN_CHANGE_BAND_3 = "LL"
+    GAIN_CHANGE_BAND_4 = "LL"
+    GAIN_CHANGE_BAND_5 = "LL"
+    GAIN_CHANGE_BAND_6_VCID_1 = "LL"
+    GAIN_CHANGE_BAND_6_VCID_2 = "HH"
+    GAIN_CHANGE_BAND_7 = "LL"
+    GAIN_CHANGE_BAND_8 = "LL"
+    GAIN_CHANGE_SCAN_BAND_1 = 0
+    GAIN_CHANGE_SCAN_BAND_2 = 0
+    GAIN_CHANGE_SCAN_BAND_3 = 0
+    GAIN_CHANGE_SCAN_BAND_4 = 0
+    GAIN_CHANGE_SCAN_BAND_5 = 0
+    GAIN_CHANGE_SCAN_BAND_6_VCID_1 = 0
+    GAIN_CHANGE_SCAN_BAND_6_VCID_2 = 0
+    GAIN_CHANGE_SCAN_BAND_7 = 0
+    GAIN_CHANGE_SCAN_BAND_8 = 0
+  END_GROUP = PRODUCT_PARAMETERS
+END_GROUP = LANDSAT_METADATA_FILE
+END
diff --git a/sat.py b/sat.py
index 7fa2228..5aad6ee 100644
--- a/sat.py
+++ b/sat.py
@@ -51,3 +51,79 @@ print(composite.size)
 cropped = composite.crop((x0, y0, x1, y1))
 
 cropped.save('cropped.png')
+
+###############################################################################
+# LAB 2
+###############################################################################
+
+# Load landsat band 4 TIF image.
+# Band 4 is near infrared.
+
+band4 = Image.open('LE07_L1TP_177025_20210723_20210818_02_T1_B4.TIF')
+
+# Claculate the NDVI.
+#
+# The NDVI is calculated by dividing
+# difference of the red and near infrared band 4 by the sum of the
+# near infrared and near infrared band 4.
+#
+# The NDVI is calculated for each pixel in the cropped image.
+#
+# The NDVI is saved as a PNG image.
+
+ndvi = band4.copy().crop((x0, y0, x1, y1))
+red = band3.copy().crop((x0, y0, x1, y1))
+result = cropped.copy()
+
+print(red.getpixel((0, 0)))
+print(ndvi.getpixel((0, 0)))
+
+# Colors for the NDVI.
+def get_color(value):
+    if value < 0.033:
+        return (255, 255, 255)
+    elif value < 0.066:
+        return (196, 184, 168)
+    elif value < 0.1:
+        return (180, 150, 108)
+    elif value < 0.133:
+        return (164, 130, 76)
+    elif value < 0.166:
+        return (148, 114, 60)
+    elif value < 0.2:
+        return (124, 158, 44)
+    elif value < 0.25:
+        return (148, 182, 20)
+    elif value < 0.3:
+        return (116, 170, 4)
+    elif value < 0.35:
+        return (100, 162, 4)
+    elif value < 0.4:
+        return (84, 150, 4)
+    elif value < 0.45:
+        return (60, 134, 4)
+    elif value < 0.5:
+        return (28, 114, 4)
+    elif value < 0.6:
+        return (4, 96, 4)
+    elif value < 0.7:
+        return (4, 74, 4)
+    elif value < 0.8:
+        return (4, 56, 4)
+    elif value < 0.9:
+        return (4, 40, 4)
+    else:
+        return (0, 0, 0)
+
+for x in range(ndvi.size[0]):
+    for y in range(ndvi.size[1]):
+        r = red.getpixel((x, y))
+        nir = ndvi.getpixel((x, y))
+        if nir + r == 0:
+            result.putpixel((x, y), get_color(0))
+        else:
+            result.putpixel((x, y), get_color((nir - r) / (nir + r)))
+
+result.save('ndvi.png')
+
+