What Is Imaging Science? Imaging Science Fundamentals

What is an Image? Your vacation photo taken with film. Your x-ray from your doctor. It is pretty safe to say that we see images in our lives all the time. There are countless forms of images. For example . . . A program on your television.

What is an Image? An image is a visual representation of an “observable” An observable is some measurable property of a person, object, or phenomenon. We all can come up with endless examples of images, but can we define what images are? We can define an “image” as a visual representation of some measurable property of a person, object, or phenomenon.

Images and Object Properties Your vacation photo taken with film. Reflected light captured on light sensitive material called film. Reflection Transmitted x-rays captured on x-ray sensitive material. Your x-ray from your doctor. Transmission So, for the case of a photograph of your vacation, the captured image is a representation of how sunlight was reflected off the scene (which consisted of many objects) then captured onto a light sensitive material called film. For an x-ray picture of your hand from the doctor, it is the transmitted x-ray captured on x-ray sensitive material. And Television is really a series of reflection images captured one after another, transmitted, received, then converted back to form moving images! Reflected light converted to electronic signal that is broadcast, received, then converted back to series of images! Reflection, Time Television program.

Other phenomena as Images Temperature map (Temperature) Ultrasound Imaging (Sound reflection) Other images weren’t even images to start with. A weather map showing the temperature of US wasn’t captured by any imaging device, but using thermometers. But the information is best represented in an image form. Some imaging systems don’t even use electromagnetic energy like light, x-ray, infrared, or microwaves. Ultrasound imaging use sound energy to get a clear view of a developing fetus. Radar use a wavelength in the microwave region to get an accurate picture of precipitation like rain and snow. Radar (Microwave reflection)

Seeing what your eyes can’t . . . Some imaging systems create visual maps of what the eye and mind can see. Others serve as transducers, converting what the eye cannot see into a visual representation that the mind can comprehend. So one of the main reason why you use an imaging system is to create visual maps of what the eye and mind can see, like photography, satellite pictures, and television. But another big reason to invent and use an imaging system is to see what your eyes and mind are not capable of. Instead, they serve as transducers, converting what the eye can not see, into a visual representation that the eye and mind can see. Example of this is x-ray, radar, and even temperature maps.

Imaging Systems Device that creates the image. Photograph X-ray Camera, film, processing X-ray X-ray machine, film Imaging systems are then the devices that creates the images. So for our example, a photograph is made not only with camera, but the film, and the processing of that film. X-ray is similar, where you need the source of x-ray, as well as the film to capture the image. And as for television, you need camera, broadcasting equipment, television receiving set, and so on. Television Camera, TV, etc.

Imaging Science Includes many scientific disciplines: Mathematics Physics Chemistry Electronics Other specific fields. Imaging science is a discipline in which we study the formation, phenomenon, and detection of images as well as analysis and processing of the information. It includes many scientific fields, including mathematics, physic, chemistry, electronics, and so on. In addition, if the imaging system is more specific to a certain field, other disciplines are important, like biology and medicine for medical imaging.

The Imaging Chain 6 Stages of Imaging 1. SOURCE: sun, star, light bulb Object Object Collection Collection Detection Detection Storage Storage Output Output The Imaging Chain 6 Stages of Imaging 1. SOURCE: sun, star, light bulb 2. OBJECT: person, flower, car 3. COLLECTION: lens, mirror 4. DETECTION: film, CCD 5. STORAGE: film, computer file 6. OUTPUT: printout, monitor Imaging systems include at least one step of the imaging chain.

Imaging is Everywhere! Applications of imaging technology can be seen almost everywhere. Application of imaging technology can be seen almost everywhere today. Now we will sample some of these technologies in use.

Astronomy: “Zooming in” The Orion Nebula (Hubble Space Telescope) The constellation of Orion (wide-field)

Astronomy: the whole spectrum Gamma Ray Milky Way in the visible wavelength region. Milky Way is the galaxy where our solar system is located. X-ray Visible Different regions of the electromagnetic spectrum allow astronomers to detect diverse phenomena in the universe. Infrared Astronomical images are important part of imaging science as scientists try to uncover the very mysteries of the universe that we live in. This is sky picture of the Milky Way is actually a sketch made in the 1940’s by an astronomer. It shows all of the sky, kind of like a map made from a globe of stars. Until the recently in our history, astronomers only had telescopes and eyes to observe stars. However, there are many other interesting things going on in the regions of electromagnetic energy that we cannot see with our naked eyes. Gamma radiation reveals . . . X ray regions show pulsars and black holes. Visible wavelengths show most of the stars, but there are many places covered with interstellar dust which blocks the visible light . . . . . . However, the Infrared can penetrate right through it, showing glowing gasses and other newly forming stars. Radiowaves show Supernova remnants and other tell tale signs of our galaxy. Notice that no stars are visible in the radio wave region. Radio Waves Images from NASA

Three views of young stars in Orion Orion Nebula region left: optical center: infrared right: Xray

Remote Sensing - Defense Visible and infrared wavelengths show visual details as well as heat signatures of aircraft and other objects. Astronomy uses a powerful optics to look UP TO the sky. Remote sensing uses a powerful optics to look DOWN FROM the sky. One of the most known remote sensing imaging is the defense area. Visible and infrared wavelengths show visual details as well as heat signatures of aircraft and other targets that may be of importance. Imaging poining that powerful Hubble telescope we saw in the previous slide down towards earth . . . Can we really read the newspaper from space? Image from Digital Globe

Remote Sensing - Environment Satellites can monitor protected forests for illegal logging activities. Remote sensing not only used in defense, but also in environmental monitoring. Illegal logging is quite difficult to spot from the ground since these loggers cut trees here and there, which cannot be seen from the ground. However, from space, these can be seen as holes in the forest. By keeping record of where the trees were, these activities can be monitored. Images from space can show invisible ozone layers which protect the earth from harmful solar radiation. By using remote sensing technologies, the extent of these ozone holes can be monitored. Other environmental remote sensing applications also include vegetation and crop stresses and water quality monitoring. Images from space show depletion of ozone from the south pole. Images from Digital Globe and NASA

Meteorology Satellite based visible image showing cloud cover. Ground based Doppler radar showing precipitation. Ground based temperature data also can be shown as an image. Meteorologist now use a variety of image data to predict weather patterns, from visual and infrared satellite images for cloud cover, Doppler radar for precipitation, and temperature, air pressure maps shown in an image form. Thanks to advanced technologies, forecasts are becoming more and more accurate. Meteorologists use a variety of image data to predict weather patterns, as well as represent data as images. Images from The WeatherChannel

Archeology/Conservation Ancient documents can be made legible by various imaging techniques. Archeologist find ancient documents from hundred and thousands of years ago. However, these documents are usually in poor shape from age, and many times illegible due to stains and fading. These documents can be made legible by various imaging techniques. For example, the image shown here is a portion of a dead sea scroll, one of the oldest written document. The original document is almost illegible from thousands of years of storage. However, since the property of the ink and the paper is different, imaging them in a different wavelengths revealed a legible inscription. Conservation is also an important part of imaging science- knowing how long the image will last, and keeping them in a good shape requires extensive knowledge of material and chemistry. Image from Chester F. Carlson Center for Imaging Science

Medical Imaging Computer Tomography (CT, CAT scan) Magnetic Resonance Imaging (MRI) Ultrasound Imaging Medical imaging has developed many useful diagnostics tools for the doctors. Computer Tomography (CAT scan), MRI, and ultrasound imaging is as common as taking a x-ray images these days. Having the option for many imaging techniques increase the chance for correct (and life saving) diagnosis. Medical imaging is used every day to provide physicians with useful data for better patient care. Images from The Visible Human and Siemens

Commercial/Personal Photography Printing Desktop publishing Commercial and personal imaging is perhaps the most commonly seen imaging systems today. They include conventional photography, digital photography, commercial printing methods, desktop publishing like laser and inkjet printing, and so on. Imaging technologies are advancing at a phenomenal rate, and due to the computing advancements, these personal imaging technologies are more and more economical. We have seen tremendous increase in imaging peripherals the last five years. We can be assured that there will be more to come!

In Summary An image is a visual representation of person, object, or phenomenon. Imaging systems create images. Imaging systems record what we see, or what we cannot see. Imaging is everywhere!