A High-Speed Black-and-White Negative Film

1960 ◽  
Vol 69 (10) ◽  
pp. 742-744 ◽  
Author(s):  
F. W. Spangler ◽  
H. R. Beilfuss
1968 ◽  
Vol 77 (10) ◽  
pp. 1136-1136
Author(s):  
W. H. Bahler ◽  
M. L. Judd ◽  
F. W. Spangler ◽  
A. L. Williams

1959 ◽  
Vol 68 (11) ◽  
pp. 735-738 ◽  
Author(s):  
Merle L. Dundon ◽  
Daan M. Zwick
Keyword(s):  

1985 ◽  
Vol 107 (2) ◽  
pp. 206-219 ◽  
Author(s):  
R. A. Taylor

Two new scanning type cotton trashmeters are being developed to indicate the amount of trash and foreign matter in lint cotton. These instruments are primarily intended to replace the current visual method of grading cotton for market quality. They both perform a two dimensional surface scan using a black and white television camera. High-speed microprocessors provide an analysis of the TV signal at video scan rates. Only a fraction of a second of time is required to complete all scanning, signal processing, and data analysis for each cotton sample exposure. This article discusses some common problems in TV image analysis and how they relate to cotton scanning. Also discussed are instrument precision and design features and a method of calibrating each instrument.


2021 ◽  
Vol 59 ◽  
pp. 57-70
Author(s):  
Om Prakash Jasuja ◽  
Suryakant Mishra ◽  
Mohinder Singh

The present research was aimed at finding out the relative effect of advancement in photocopier technology on the analysis of handwriting line quality features in multi-generational photocopies. Five subsequent multi-generational photocopies of 50 signature samples from different individuals which were produced by 75 black and white photocopiers were used for line quality assessments. Variations in line quality features in different photocopy generations, such as: smooth edges or ragged edges, broken or continuous stroke, fine tapering changes, and some identification details of features like pen lifts, retouching, and hesitation were carefully observed in sample photocopies, which were recorded according to the brand and model of photocopier machines, as well as their size and speed. The results of the study revealed that raggedness in line was often observed in third generation (G3) and higher generations, in samples produced by some low speed copiers (copying speed < 30 cpm) or very high speed copiers (copying speed ≤ 80 cpm). However, their line quality was still found to be good enough for handwriting analysis up to the fifth generation (G5) in photocopy samples produced by some medium speed copiers (copying speed 30 to 50 cpm). It was, however, observed that, usually, continuity of line and smoothness of line were appreciably lost in G3 and higher generations in photocopies which were produced by portable desktop printers. Exceptionally, certain artifacts that are usually found in some higher generation copies were conspicuously absent in all photocopy generations (G1–G5) which were produced by some advanced third generation photocopiers. Hopefully, the information obtained from the study will be found useful to document examiners when examining certain cases involving multi-generations of photocopier reproductions.


SMPTE Journal ◽  
1985 ◽  
Vol 94 (7) ◽  
pp. 724-734 ◽  
Author(s):  
Richard C. Sehlin ◽  
Glenn L. Kennel ◽  
Edward F. Ortman ◽  
Frank R. Reinking
Keyword(s):  

SMPTE Journal ◽  
1985 ◽  
Vol 94 (7) ◽  
pp. 735-742
Author(s):  
Sadayuki Yamaryo ◽  
Shingo Ishimaru ◽  
Kazuhiko Takemura
Keyword(s):  

1968 ◽  
Vol 77 (10) ◽  
pp. 1140-1140
Author(s):  
W. H. Bahler ◽  
M. L. Judd ◽  
F. W. Spangler ◽  
A. L. Williams

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