Raster to Vector

Attribute Fill => Raster to Vector

The Atribute Fill - Raster to Vector tool is used to extract statistics of a Raster Layer using a Vector Layer as reference. New attributes will be added to the vector layer and filled with those statistics. The vector layer can be a cellular space or any vector layer (polygons) overlapping the raster. For each cell or polygon of the vector layer, one attribute for each selected statistic will be created and filled. This process is performed for each selected band of the raster.


Raster without polygons overlapping	Raster with polygons overlapping

It is accessed through:

Processing > Attribute Fill > Raster to Vector...

Input Raster: select a raster layer where the statistics will be extracted.

Optionally, click on No Data Value and inform the pixel value that should not be considered in the calculus.

Input Vector: select the vector layer overlapping the raster.

Optionally, click on Only Selected if some objects (polygons or cells of the vector layer) are selected in the MAP DISPLAY. The Statistics will be calculated only for these objects.

Iterator Strategy:

Center of pixel: the pixel value will be considered if its centroid is inside the geometry overlapping it.

Box of pixel: the pixel value will be considered if its bounding box intersects the geometry overlapping it.

Note 1: the pixel bounding box will be computed internally and it can be very time consumming.
Note 2: when to consider to use this strategy?

when the pixel size is greater than the geometry overlapping it and the statistics selected at step 6 involves area, like " Percentage of each class by area". In this case it will be considered only the intersection of the pixel bounding box and the geometry overlapping it.

Bands: Select one or more bands to apply the statistics select below.
Statistics: click over one or more statistics to select then (see table bellow).

NOTE: all statistics options will generate one attribute for each band, except Percentage of each class by area
Percentage of each class by area: it is recomended only for classified rasters, otherwise will generate one attribute for each distinct pixel value for each band.

Inform the Output Repository by clicking on:

to select the output directory and also inform the new layer name to store the result, or

to select the Data Source and inform the connection parameters

Inform the new Layer Name to store the result.

Click OK to perform the operation or Cancel to close the interface.

Statistics options

Statistics	Attribute(s) prefixed by band B0, B1...	Overlapping geometry
Value	B0_Value	Points/Polygons
Minimum value	B0_Min_Val	Polygons
Maximum value	B0_Max_Val	Polygons
Mean	B0_Mean	Polygons
Sum of values	B0_Sum	Polygons
Total number of values	B0_Count	Polygons
Total not null values	B0_Valid_Count	Polygons
Standard deviation	B0_Standar	Polygons
Variance	B0_Varianc	Polygons
Skewness	B0_Skewnes	Polygons
Kurtosis	B0_Kustosi	Polygons
Amplitude	B0_Amplitu	Polygons
Median	B0_Median	Polygons
Coefficient variation	B0_Var_Coe	Polygons
Mode	B0_Mode	Polygons
Percent of each class by area	B0_<classNameX> *	Polygons

* It will create one attribute per class (per band). If the raster layer is not classified, it will gererate one attribute for each distinct pixel value. As as example, a raster file of 8 bits and 2 bands selected will generate all this attributes:  B0_0, B0_1,...,B0_255, B1_0, B1_1,...,B1_255.

NOTE: Check the results of a celular space (vector layer where the polygons are regular cells) overlapping a raster file with the following parameters:
            Bands: (0,1)
            Statistics: Mininum Value, Maximun Value, Mean and Variance.
            Note that the attributes generated for each cell are prefixed by the band identification ('B0_' and 'B1_').

Table with new attributes