DIGITAL IMAGE PROCESSING – CT EXAM
WITH CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST 2024 – 2025 ALREADY GRADED A+
Image compression - ANSWERS-Digital compression refers to using one or more
of many, software and or hardware techniques to reduce information by
removing unnecessary data, Remaining information then coded and either
transmitted or stored in an archive or storage media Using decompression, the
users equipment later decodes the information and fills in a representation of the
data that was removed during compression
Types of image compression - ANSWERS-lossless or reversible compression 2:1 or
3:1, no loss of information, doesn't involve the process of quantization but makes
use of image transformation and encoding to provide a compressed image, Lossy
or irreversible compression 10:1 or 50:1, some information lost, involves image
transformation, quantization, and encoding, not used by radiologists in primary
diagnosis due to legal concerns and incorrect diagnosis , At low compression
ratios (8:1 or less) the image is still visually acceptable, compression tolerance,
the maximum compression in which the decompressed image is acceptable for
interpretation and aesthetics
, Visual impact of irreversible compression on digital images - ANSWERS-As
compression ratios increase less storage space is required and transmission
speeds increase but at the expense of image quality degradation ,Compression
ratio of 8:1 or less visually acceptable
Image synthesis overview - ANSWERS-An advantage of digital image processing,
Attenuation data is collected from the patient by the detectors, sent to the
computer, and digitized by the ADC. Special reconstruction, algorithim(filtered
back projection) is used to build up a digital CT image and us then converted to
gray scale for viewing. Displayed images can be manipulated with digital imaging
software to perform such processing as windowing, image reformatting, and 3D
visualization
Image processing hardware - ANSWERS-ADC, Image storage, Image display, Image
processor, Host computer, DAC
Image processing hardware - ANSWERS-Data acquisition, CT x-Ray tube and
detectors. Digitizer, analog signal is converted into digital form. Image memory,
digitized image is held for further processing. DAC, converts digital image to
analog for viewing, Internal image processor, high speed processing of the input
digital data. Host computer, primary component capable of performing several
functions
CT as a digital image processing system - ANSWERS-The slice of the patient is
divided into small regions called voxels because the dimension of depth(slice
thickness) is added to the, pixel, The voxels are sampled when x-rays pass through
them. The signal from the detector is in analog firm and must be converted into
digital form before it can be sent to the computer for processing, The analog
signal is quantized and changed into a digital array for input into the computer.
WITH CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST 2024 – 2025 ALREADY GRADED A+
Image compression - ANSWERS-Digital compression refers to using one or more
of many, software and or hardware techniques to reduce information by
removing unnecessary data, Remaining information then coded and either
transmitted or stored in an archive or storage media Using decompression, the
users equipment later decodes the information and fills in a representation of the
data that was removed during compression
Types of image compression - ANSWERS-lossless or reversible compression 2:1 or
3:1, no loss of information, doesn't involve the process of quantization but makes
use of image transformation and encoding to provide a compressed image, Lossy
or irreversible compression 10:1 or 50:1, some information lost, involves image
transformation, quantization, and encoding, not used by radiologists in primary
diagnosis due to legal concerns and incorrect diagnosis , At low compression
ratios (8:1 or less) the image is still visually acceptable, compression tolerance,
the maximum compression in which the decompressed image is acceptable for
interpretation and aesthetics
, Visual impact of irreversible compression on digital images - ANSWERS-As
compression ratios increase less storage space is required and transmission
speeds increase but at the expense of image quality degradation ,Compression
ratio of 8:1 or less visually acceptable
Image synthesis overview - ANSWERS-An advantage of digital image processing,
Attenuation data is collected from the patient by the detectors, sent to the
computer, and digitized by the ADC. Special reconstruction, algorithim(filtered
back projection) is used to build up a digital CT image and us then converted to
gray scale for viewing. Displayed images can be manipulated with digital imaging
software to perform such processing as windowing, image reformatting, and 3D
visualization
Image processing hardware - ANSWERS-ADC, Image storage, Image display, Image
processor, Host computer, DAC
Image processing hardware - ANSWERS-Data acquisition, CT x-Ray tube and
detectors. Digitizer, analog signal is converted into digital form. Image memory,
digitized image is held for further processing. DAC, converts digital image to
analog for viewing, Internal image processor, high speed processing of the input
digital data. Host computer, primary component capable of performing several
functions
CT as a digital image processing system - ANSWERS-The slice of the patient is
divided into small regions called voxels because the dimension of depth(slice
thickness) is added to the, pixel, The voxels are sampled when x-rays pass through
them. The signal from the detector is in analog firm and must be converted into
digital form before it can be sent to the computer for processing, The analog
signal is quantized and changed into a digital array for input into the computer.
