Spotlight - On Forensic Image Analysis

Forensics

I am going to keep working towards a Forensics Manual throughout the year.  I will be trying to put some order on things in the near future and may start to pull together some sample analysis in a standard format so that it is possible to see where the various forensic tools start to fall into place.  I have no doubt this aspect of the blog may be boring for many of you but for me this is the heart of this whole exercise.  Hopefully the value of it will be clearer in time.  I must stress that this is very much an exercise in trial and error.  I have no training in digital forensics, nor access to a wealth of research material.  This is purely a case of getting to know the existing software tools, their uses and limitations, identifying challenges and trying to find novel ways to overcome them.

Most birders, myself included, are probably content to analyse most bird images using a web browser or a simple photo viewer with only a zoom tool for closer analysis.  How many of us actually take the time to download an image and open it up in Photoshop or a similar package, to analyse it further? Most of the time a web browser or image viewer may be sufficient for ID purposes.  But when the ID is a challenge it certainly helps to apply some form of forensic analysis.  Learning what tools to use, when to apply them and by how much is what forensic image analysis is all about.

What I am working on ultimately with this series of postings is a guide to help with and encourage a more critical analysis when one is required.  Wouldn't it be great if a forum existed where contributors could put up bird ID images for analysis and others could take the images,work on them and resubmit together with their analysis.  I think that could be very instructive for birders learning how to ID birds from photos.  I am happy to facilitate that through this blog if there is an appetite for it.  For now I am just going to keep working on useful tools and gaining insights. 



FORENSICS - AN INTRODUCTION

Maximizing Content

MAXIMISING IMAGE CONTENT

BIT DEPTH LIMITATIONS

MAXIMIZING IMAGE SHARPNESS

Gaussian Analysis

AN INTRODUCTION TO GAUSSIAN ANALYSIS

GAUSSIAN ANALYSIS - OVEREXPOSURE

GAUSSIAN ANALYSIS - UNDEREXPOSURE

GAUSSIAN ANALYSIS - DEFOCUS

GAUSSIAN ANALYSIS - WHITE BALANCE

GAUSSIAN ANALYSIS - ARTEFACTS

Working in RAW 

CSI RAW

MAXIMISING IMAGE CONTENT

HIGH DYNAMIC RANGE IMAGING (HDRI)

FRINGE ARTEFACTS WHILE WORKING IN RAW

Lighting

ANALYSIS OF SHADOWS

LIGHTING AND SHADOW DIRECTION

IMAGE LIGHTING TOOLS

LAMBERT'S COSINE LAW

'COSINE FOURTH' LAW OF ILLUMINATION FALLOFF

POLARIZATION

Other Image Modification Tools

MODIFIED IMAGES - BEFORE AND AFTER

Colour

COLOUR BY NUMBERS

COLOUR SAMPLING

COLOUR PROFILING (CP)

PROS AND CONS OF BOOSTING SATURATION

UV IMAGING

Gestalt

A GESTALT FIELD GUIDE

GESTALT AND VIDEO - A USEFUL TIP

SIZE MATTERS

SIMPLE 3D MODELLING FROM 2D IMAGES

Other Relevant Postings

IMAGE ARTEFACTS

TONAL GRADIENT ILLUSIONS

THE NORMALIZING OF IMAGE DOCTORING

COMPARATIVE PHOTOGRAPHIC ANALYSIS (CPA)

FEMTO-PHOTOGRAPHY