Image Resolution

What is Resolution?

Image resolution quantifies how much detail can be seen in an image.  Higher resolution images contain more detail than lower resolution images.   In digital imagery, this detail is made up of pixels, which are square dots, that when placed next to each other, begin to make up the image.  In aerial imagery, resolution is quantified by the actual length of each pixel as it would be measured on the ground. 

The image below is enlarged to show the individual pixels. 

Pixel_example

The image below shows the individual pixels from the image above.  The size of each pixel is the same, so the size of features in the image can be measured. 

Pixel_example_3

Why does Blue Earth Imaging offer different resolutions?

Higher resolution images will have smaller pixels and therefore, more information packed into the same area.  This resolution allows more information to be interpreted from the imagery.  However, capturing higher resolution imagery requires that the imagery be collected at a lower altitude and also demands significantly more storage and data processing.  The following demonstration shows the same image viewed at various resolutions.  As the resolution is decreased, the ability to determine details in the image is reduced. 

1/32 meter / pixel
 1/16 meter / pixel 1/8 meter / pixel 1/4 meter / pixel
1.25 inches / pixel 2.5 inches / pixel 5 inches / pixel 10 inches / pixel
16,384 pixels 4,096 pixels 1,024 pixels 256 pixels
8,137 MB / mi2
 		 2,034 MB / km2
 508 MB / km2
 127 MB / km2

Sample_1

Sample_2

1/2 meter / pixel 1 meter / pixel 2 meters / pixel 4 meters / pixel
20 inches / pixel 40 inches / pixel 6.5 feet / pixel 13 feet / pixel
64 pixels 16 pixels 4 pixels 1 pixel
31 MB / mi2 7.9 MB / mi2 2.0 MB / mi2 0.50 MB / mi2

Image resolution should correspond to the features that will be identified and measured in the imagery.  If small features need to be identified, high resolution imagery will be required.  Larger features do not require high resolutions. 
  • The resolution of an image needs to be about 2X the length of the object, to pick out the object from the background.  This allows counting.  (For an automobile that is 2 meters wide, a resolution of 1 meter / pixel is required)
  • When the resolution is 8-10X the length of the object, the object can be identified.  (For an automobile that is 2 meters wide, a resolution of 1/4 meter / pixel is required)
  • As the resolution is increased further, the type of automobile can be determined:  Pickup Truck
  • As the resolution is increased even further, a trained observer may even be able to determine the make of the automobile


Typical Aerial Imaging Resolutions:

Blue Earth Imaging typically collects imagery with resolutions from 1/8th meter to 1 meter (5 inch to 40 inch).

1 Meter Resolution 1/2 Meter Resolution 1/4 Meter Resolution
40 inches per pixel 20 inches per pixel 10 inches per pixel

1M_res1/2M_res1/4M_res
(Click for more detail, [esc] to exit)

1/8 Meter Resolution
5 inches per pixel

1/2M_res
(Click for more detail, [esc] to exit)


Very High Resolution Imagery:

Blue Earth Imaging can collect imagery with resolutions as high as 1/64th meter (0.6 inch).  Very high resolution imagery requires low flight altitudes and can require special coordination with air traffic control.  Please contact us to discuss your specific requirements. 

1/32 Meter (1.25 in) Resolution

1/32M_res
(Click for more detail, [esc] to exit)

1/64 Meter (0.6 in) Resolution

1/64M_res
(Click for more detail, [esc] to exit)