import rasterio
import matplotlib.pyplot as plt
import numpy as np
import os
def visualize_dem(input_path="dted/dem.tif", output_path="dted/dem_preview.png"):
if not os.path.exists(input_path):
print(f"File not found: {input_path}")
return
with rasterio.open(input_path) as src:
data = src.read(1)
# Mask out nodata values if present
if src.nodata is not None:
data = np.ma.masked_equal(data, src.nodata)
plt.figure(figsize=(10, 8))
plt.imshow(data, cmap='terrain')
plt.colorbar(label='Elevation (m)')
plt.title(f"DEM Preview: {os.path.basename(input_path)}")
plt.axis('off')
plt.savefig(output_path, bbox_inches='tight', dpi=150)
print(f"Saved preview to {output_path}")
plt.close()
if __name__ == "__main__":
visualize_dem()
