Digital Conversion of Single-Use Camera Ranging Lab Michael Spaeth SUC Tech Center Eastman Kodak Company

Ranging Lab

Problems with Ranging Lab Negatives are read via microscope –Tiring for observer Human differences –What you see as a line pair, I may not Red tint of color AgX negative

Digital Method - Theory Digitally sample images –Whether with CCD array or film scanner Run images through a slanted-edge test to find MTF Compare MTF’s to find ‘best’ focus

Slanted-Edge Algorithm Slanted-Edge software Written in Matlab Needs high contrast in target Needed to be converted to IDL

Slanted-Edge Test - Matlab

IDL Conversion Test

Ranging Lab Program Loops Slanted-Edge Analysis Compares MTF values to determine ‘best’ focus

Ranging Lab Program Demo

Problems With Method Inconsistant –Does not return same value each time through –Possible Reason – low contrast in images, creating high error in MTF calculation –Possible Solution – use target with higher contrast alter image to raise contrast

Problems With Method All the plots are the same –Possible Reason – multiple systems influencing system MTF –Possible Solutions – Analyze all systems other than optics and subtract MTF for these systems Reduce number of systems in process