Cloud filtering Landsat collection 2 time series by region

Question

I'm working on creating an NDVI time series and I'm trying to filter out clouds over a specific region so I wont get huge gaps in the time series.

Is there a way to reduce the extent by cloud percent?

Part of the code:

var extent = 
    /* color: #44c239 */
    /* displayProperties: [
      {
        "type": "rectangle"
      }
    ] */
    ee.Geometry.Polygon(
        [[[35.66951628813774, 33.212344469176244],
          [35.66951628813774, 33.18720738523013],
          [35.69560881743462, 33.18720738523013],
          [35.69560881743462, 33.212344469176244]]], null, false);
          
// Applies scaling factors for LS 457.
function applyScaleFactors457(image) {
  var opticalBands = image.select('SR_B.').multiply(0.0000275).add(-0.2);
  var thermalBand = image.select('ST_B6').multiply(0.00341802).add(149.0);
  return image.addBands(opticalBands, null, true)
              .addBands(thermalBand, null, true);
}

var startdate = '2000-08-01';
var enddate= '2021-08-01';

var LS7Collection = ee.ImageCollection('LANDSAT/LE07/C02/T1_L2')
  .filterBounds(extent)
  .filterDate(startdate, enddate)
  .map(applyScaleFactors457);

//filer clouds by region ????
var c = LS7Collection.filterBounds(extent);

var getQABits = function(image, start, end, newName) {
    // Compute the bits we need to extract.
    var pattern = 0;
    for (var i = start; i <= end; i++) {
       pattern += Math.pow(2, i);
    }
    // Return a single band image of the extracted QA bits, giving the band
    // a new name.
    return image.select([0], [newName])
                  .bitwiseAnd(pattern)
                  .rightShift(start);
};

var clouds = function(image) {
  // Select the QA band.
  var QA = image.select(['SR_CLOUD_QA']);
  // Get the internal_cloud_algorithm_flag bit.
  return getQABits(QA, 1,1, 'Clouds').eq(1);
};

var cloudper = function(image){
  return image.reduceRegion({
  reducer: ee.Reducer.mean(),
  geometry: extent,
  scale: 30,
  maxPixels: 1e9
})};

//var LS7Collection = LS7Collection.filter(ee.Filter.lessThan(cloudper(c.map(clouds)), 10));
//print(LS7Collection);

my full code: https://code.earthengine.google.com/?accept_repo=users/tomcol/personal

Answer 1

I found one way of doing this.

By cliping the image collection to the region of interest and then applying a "CLOUD_COVER" filter with wanted cloud percent.

I used this code:

var LS8 = ee.ImageCollection("LANDSAT/LC08/C02/T1_L2")
var LS8Collection = LS8.map(function(image){return image.clip(regions)});
var LS8Collection = LS8Collection.filter(ee.Filter.lte('CLOUD_COVER_LAND', 10));
print(LS8Collection);