PPT ON JPEG
Transcript of PPT ON JPEG
![Page 1: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/1.jpg)
![Page 2: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/2.jpg)
WHY IMAGE COMPRESSION IS REQUIRED?
CONSIDER A STANDARD DEFINITION(SD) MOVIE USING 720×480×24 BIT PIXEL ARRAYS WITH 30 FPS.
A DIGITAL MOVIE IS A SEQUENCE OF VIDEO FRAMES OF WHICH EACH FRAME IS A STILL IMAGE.
FOR 30 FRAMES 30 FRAMES/SEC×(720×480) PIXELS/FRAME×3
BYTES/PIXEL=31104000 BYTES/SEC. FOR A 2 HR MOVIE 31104000 BYTES/SEC×(60)^2 SEC/HR×2 HRS=2.24×10^11 BYTES
![Page 3: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/3.jpg)
WHAT ARE IMAGE FORMATS,IMAGE CONTAINERS &IMAGE COMPRESSION STANDARDS?
![Page 4: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/4.jpg)
The JPEG StandardJPEG is an image compression standard
which was accepted as an international standard in 1992.Developed by the Joint Photographic
Expert Group of the ISO/IECFor coding and compression of
color/gray scale imagesYields acceptable compression in the
10:1 range
![Page 5: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/5.jpg)
The JPEG StandardJPEG is a lossy compression technique
Based on the DCTJPEG is a general image compression
technique independent ofImage resolutionImage and pixel aspect ratioColor systemImage complexity
A scheme for video compression based on JPEG called Motion JPEG (MJPEG) exists
![Page 6: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/6.jpg)
BLOCK DIAGRAM OF JPEG
![Page 7: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/7.jpg)
CONSTRUCTING N×N SUB IMAGES WITH DCT
![Page 8: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/8.jpg)
FORWARD &INVERSETRANSFORMS
FOURIER TRANSFORMWALSH HADAMARD TRANSFORMDISCRETE COSINE TRANSFORM
![Page 9: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/9.jpg)
The image is divided up into 8x8 blocks2D DCT is performed on each blockThe DCT is performed independently for each blockThis is why, when a high degree of compression is requested, JPEG gives a “blocky” image result
N
vy
N
uxpCC
NDCT
N
y xy
N
xvuuv 2
)12(cos
2
)12(cos
2
1 1
0
1
0
![Page 10: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/10.jpg)
![Page 11: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/11.jpg)
THE SIGNIFICANT FACTOR THAT EFFECTS TRANSFORM CODING ERROR AND COMPUTATIONAL COMPLEXITY IS SUB IMAGE SIZE WHICH ARE USUALLY 8×8 AND 16×16.
RECONSTRUCTION ERROR VERSUS SUB IMAGE SELECTION
![Page 12: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/12.jpg)
BIT ALLOCATION THE RECONSTRUCTION ERROR ASSOCIATED WITH THE
TRUNCATED SERIES EXPANSION IS A FUNCTION OF NUMBER AND RELATIVE IMPORTANCE OF TRANSFORM COEFFICIENTS THAT ARE DISCARDED,AS WELL AS THE PRECISION THAT IS USED TO REPRESENT THE RETAINED COEFFICIENTS.
RETAINED COEFFICIENTS ARE SELECTED BASED ON TWO TYPES NAMELY
ZONAL CODING THRESHOLD CODING
![Page 13: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/13.jpg)
BIT ALLOCATION CODINGSZONAL CODING IS DONE BASED ON THE
MAXIMUM VARIANCE.THRESHOLD CODING IS DONE BASED ON
THE MAXIMUM MAGNITUDE.
![Page 14: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/14.jpg)
CONSIDER A 8×8 SUB IMAGE
![Page 15: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/15.jpg)
LEVEL SHIFTING THE PIXELS
![Page 16: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/16.jpg)
BY FORWARD DCT
![Page 17: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/17.jpg)
NORMALIZATION OR QUANTIZATION MATRIX
![Page 18: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/18.jpg)
TRANSFORMED ARRAY AFTER QUANTIZATION
![Page 19: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/19.jpg)
ZIG-ZAG ORDERING OF JPEG IMAGE
![Page 20: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/20.jpg)
DCT COEFFICIENT MATRIX
![Page 21: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/21.jpg)
AFTER DENORMALIZATION
![Page 22: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/22.jpg)
INVERSE DCT TRANSFORM
![Page 23: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/23.jpg)
ADDING 128 TO THE ENTRY
![Page 24: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/24.jpg)
DIFFERENCES BETWEEN ORIGINAL &RECONSTRUCTED SUB IMAGE
![Page 25: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/25.jpg)
Examples of varying JPEG compression ratios
![Page 26: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/26.jpg)
CONCLUSION BASED ON THE COMPRESSION RATIO
IMAGES WITH LESS MEMORY ARE OBTAINED.
THERE ARE JPEG COMPRESSIONS WHICH ARE LOSSLESS USED IN MEDICAL IMAGING , SPACE
&RESEARCH FIELDS.MEDIA COMPRESSION IS INDISPENSABLE
EVEN AS STORAGE AND STREAMING CAPACITIES INCREASE
![Page 27: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/27.jpg)
![Page 28: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/28.jpg)
![Page 29: PPT ON JPEG](https://reader033.fdocuments.us/reader033/viewer/2022061209/548d25ccb47959227e8b45b9/html5/thumbnails/29.jpg)