I have a 10 meter resolution raster and 100 meter fishnet of the same area. One grid of 100 meter resolution can cover hundered 10 meter pixels at maximum. I want to count the number of ten meter pixels comming in 100 meter grid. The pixel count should follow the condition that the 10 meter pixel should totally lie inside it.
Thanking you
This can be done mathematically and you will need to check for grid alignment in both the x and y dimensions. If you are aligned in both x and y then as you say you will have 100 pixels in one grid square. If you are aligned in one of the two axis and misaligned in one of the axis you will have 90 complete pixels to each grid square (as you lose a 10 pixel row or column that are not entirely inside the grid). If you are misaligned in both axis you will have 81 whole pixels per grid.
Extending that answer to a general case of an overlaid square grid of size n-by-n pixels:
- If the grid lines are aligned in x and y the contained pixels per grid will be n2.
- If the grid lines are misaligned in only one of x or y the contained pixels will be n2-n
- If the grid lines are misaligned in both x and y the contained pixels will be (n-1)2
Hope that helps.
This number can be lower if the axes of the grid are not parallel to the edges of the pixels. At the moment I do not know how to find the minimum.
Dear james,
I guess you are not clear with my question. You are saying the different possibilities of grid alignment and when the grid is fully occupied by pixels. Firstly I had a raster image of urban area with 10 meter resolution and then I created the fishnet on it with 100*100 meters. Now I just want to find out how many 10 meter pixels are coming in 100 meter grid.
I tried using the zonal histogram, zonal statistics and clip tools in arcgis but I didn't get the result.
Thanking you,
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