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Image Size and Resolution - Introduction

Image Size and Resolution

As discussed on the Images page, a scientist wishes to have the largest possible images and those with the largest possible resolution. Below we show how changing the size and resolution of an image changes our view of that image.

Small image Medium size image Full size image

The same image shown with three different sizes, each 10 times larger than the image to its left. The original image is The Artist's Father, Reading by Paul Cezanne.

In the figure above, the same image is shown at 3 different sizes. The image in the middle is 10 times bigger than the image on the left, and the image on the right is 10 times bigger than the image in the middle. The size of the image is important!

Using the tiny image on the left, we have no idea what we are looking at; though, we know "something" is there. The image in the middle allows us to barely make out that "something" as a human being. The image on the right allows us to identify the "something" as a painting of Paul Cezanne's father reading a newspaper. An astronomer wants a detector that can produce the largest image possible.

Image size is only a part of the whole 'image' issue....the resolution can be just as important.

Low spatial resolution image Full spatial resolution image

The same image shown with two different resolutions. The right image has 9 times the spacial resolution of the left image. The original image is The Artist's Father, Reading by Paul Cezanne.

The figure above shows the same image at the same size, but at 2 resolutions. The image on the right has 9 times the spatial resolution as the one on the left does. Now you can see why having a value of the spatial resolution be as big as possible is very important to an astronomer... the bigger (or better) the resolution, the more details we can see, and the more we can learn.

Updated: July 2013




 

A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC

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