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    "tags": []
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   "source": [
    "import rastereasy"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "41eb0042-eb52-443f-8197-8db22a836331",
   "metadata": {},
   "source": [
    "# Pixel vs geographical coordinates "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
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     "text": [
      "Help on method pixel2latlon in module rastereasy.rastereasy:\n",
      "\n",
      "pixel2latlon(i, j) method of rastereasy.rastereasy.Geoimage instance\n",
      "    Convert pixel coordinates to geographic coordinates (latitude, longitude).\n",
      "\n",
      "    This method transforms a pixel location (row, col) in the image to the\n",
      "    corresponding point defined by its latitude and longitude.\n",
      "\n",
      "    Parameters\n",
      "    ----------\n",
      "    i : int\n",
      "        Row index (vertical position) in the image\n",
      "    j : int\n",
      "        Column index (horizontal position) in the image\n",
      "\n",
      "    Returns\n",
      "    -------\n",
      "    tuple of float\n",
      "        The geographic coordinates as (latitude, longitude)\n",
      "\n",
      "    Examples\n",
      "    --------\n",
      "    >>> # Convert pixel coordinates to geographic location\n",
      "    >>> row, col = 500, 700\n",
      "    >>> latitude, longitude = image.pixel2latlon(row, col)\n",
      "    >>> print(f\"Pixel ({row}, {col}) is at lat/lon: ({latitude}, {longitude})\")\n",
      "    >>>\n",
      "    >>> # Find coordinates of image corners\n",
      "    >>> nw_lat, nw_lon = image.pixel2latlon(0, 0)  # Northwest corner\n",
      "    >>> se_lat, se_lon = image.pixel2latlon(image.shape[0]-1, image.shape[1]-1)  # Southeast\n",
      "    >>> print(f\"Image covers from ({nw_lat}, {nw_lon}) to ({se_lat}, {se_lon})\")\n",
      "\n",
      "    Notes\n",
      "    -----\n",
      "    - The image must be georeferenced (have valid CRS and transform)\n",
      "    - Pixel coordinates typically start at (0, 0) in the upper-left corner of the image\n",
      "    - For most projections, latitude increases going north and longitude increases going east\n",
      "\n",
      "Help on method latlon2pixel in module rastereasy.rastereasy:\n",
      "\n",
      "latlon2pixel(coord_lat, coord_lon) method of rastereasy.rastereasy.Geoimage instance\n",
      "    Convert geographic coordinates (latitude, longitude) to pixel coordinates.\n",
      "\n",
      "    This method transforms a point defined by its latitude and longitude to\n",
      "    the corresponding pixel location (row, col) in the image.\n",
      "\n",
      "    Parameters\n",
      "    ----------\n",
      "    coord_lat : float\n",
      "        Latitude of the point\n",
      "    coord_lon : float\n",
      "        Longitude of the point\n",
      "\n",
      "    Returns\n",
      "    -------\n",
      "    tuple of int\n",
      "        The pixel coordinates as (row, col) or (i, j)\n",
      "\n",
      "    Examples\n",
      "    --------\n",
      "    >>> # Convert a geographic location to pixel coordinates\n",
      "    >>> latitude, longitude = 42.36, -71.06  # Boston, MA\n",
      "    >>> row, col = image.latlon2pixel(latitude, longitude)\n",
      "    >>> print(f\"This location is at pixel ({row}, {col})\")\n",
      "    >>>\n",
      "    >>> # Check if a specific location is within the image extent\n",
      "    >>> row, col = image.latlon2pixel(latitude, longitude)\n",
      "    >>> in_bounds = (0 <= row < image.shape[0]) and (0 <= col < image.shape[1])\n",
      "    >>> print(f\"Location is within image: {in_bounds}\")\n",
      "\n",
      "    Notes\n",
      "    -----\n",
      "    - The image must be georeferenced (have valid CRS and transform)\n",
      "    - If the point is outside the image extent, the function will still return pixel coordinates, but they may be outside the valid image dimensions\n",
      "    - Row (i) corresponds to the vertical position (along latitude)\n",
      "    - Column (j) corresponds to the horizontal position (along longitude)\n",
      "\n"
     ]
    }
   ],
   "source": [
    "name_im='./data/demo/sentinel.tif'\n",
    "image=rastereasy.Geoimage(name_im)\n",
    "help(image.pixel2latlon)\n",
    "help(image.latlon2pixel)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "de8e3433-47e6-4c72-b24d-10008f12a81d",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Coord :  3 19   (lat,lon) =  7.085895234623746 38.3469798575148\n",
      "Coord :  80 25   (lat,lon) =  7.078931083837443 38.34753293909697\n",
      "----\n",
      "(lat,lon) =  7.085895234623746 38.3469798575148 Coord :  3 19\n",
      "(lat,lon) =  7.078931083837443 38.34753293909697 Coord :  80 25\n",
      "diff ppixels :  77 6  - diff lat lon :  -0.0069641507863034136 0.0005530815821686019\n"
     ]
    }
   ],
   "source": [
    "row1 = 3\n",
    "col1 = 19\n",
    "row2 = 80\n",
    "col2 = 25\n",
    "lat1,lon1=image.pixel2latlon(row1,col1)\n",
    "lat2,lon2=image.pixel2latlon(row2,col2)\n",
    "print('Coord : ',row1,col1,'  (lat,lon) = ', lat1,lon1)\n",
    "print('Coord : ',row2,col2,'  (lat,lon) = ', lat2,lon2)\n",
    "print('----')\n",
    "est_row1,est_col1=image.latlon2pixel(lat1,lon1)\n",
    "est_row2,est_col2=image.latlon2pixel(lat2,lon2)\n",
    "\n",
    "print('(lat,lon) = ', lat1,lon1,'Coord : ',est_row1,est_col1)\n",
    "print('(lat,lon) = ', lat2,lon2,'Coord : ',est_row2,est_col2)\n",
    "\n",
    "print('diff ppixels : ',row2-row1,col2-col1,' - diff lat lon : ',lat2 - lat1,lon2 - lon1)"
   ]
  }
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