2-3 Flashcards
(14 cards)
types of digital images (4)
- monochromatic/ binary
- greyscale
- truecolour/ RGB
- indexed
are digital image types the same as image file types ?
no
monochromatic/ binary image
type, bit, use
no colour, only 2 pixel types: 0 (black), 1 (white)
needs only one bit (0 or 1)
suitable for text, fingerprints or architectural plans
greyscale image
type, use
has no colour, only shades of grey: brightness values ranging from 0 (black) to 255 (white)
used in xrays, MRI, CT
sufficient for recognising most objects
how many bits in 1 byte
8 bits
truecolour/ RGB image
type, component, non uses
represented by colours Red, Blue and Green
each component is 0 to 255, (16,777,216 diff colours)
not used is xrays, MRIs or CTs as those devices cannot detect colour
what is indexed image type (2)
uses colour map/ colour pallette
pixels do not represent its colour, but an index to the colour in the map
how many bits in 1 pixel for RGB
24 bits, 8 for R G and B
what is a colour map (3)
an m-by-3 matrix
Each row specifies red, green, and blue components of single color from image
pixel values in image matrix are direct indices into the colourmap & often stored with an indexed image and is automatically loaded with the image.
can u calculate file size yet
yes or no 0_0
name some digital file image types (6)
b,b,g,t,j,d
BIN, BMP, GIF, TIFF, JPEG, DICOM
what does DICOM stand for?
DIaCOiM
Digital Imaging and Communication in Medicine
DICOM use (4) ?
def
image no.
image obs.
st ?
- Used in defining an image format (.dcm)
- May hold single or multiple images.
- Thus files may be observed as slices/ frames of a 3D object.
- Standard for medical digital-imaging modalities.
DICOM files contains (2)?
Header → contains patient and image information, size, number of slices, modality
Image data → May be compressed image
