 Image Integration Newsletter |
Putting Quality in the Digital Image December 2007 |
In this issue:
New Website - Check out our new website!
Image Phi - Determine your customer's picture taking experience and optimize your design to those needs. New tool available from Image Integration.
Current Activities - A preview of some interesting results from a survey of camera phones showing the lack of correlation between image quality and the conditions under which pictures are typically taken.
We invite you to visit the revised Image Integration website.
www.imagintegration.com
The new site features the introduction of the first of a series of software tools designed to facilitate your use of many existing image analyses packages. These tools are designed to help you identify the appropriate measurements for characterizing your imaging system and to interpret these measurements in terms of perceived image quality.
Are your cameras designed for your customer’s usage?
Last
September, while visiting Denver, I took the following two images with
my 2 Mega pixel camera phone.
The first image was taken, handheld, in Norman Koren’s [www.Imatest.com]
living room. The next image was taken at mid day in brilliant Rocky
Mountain sunshine.The dramatically different levels of quality make it clear that there is no single characterization of the camera that is adequate to describe its performance. The excellent sharpness that the camera achieved in brightly illuminated scene conditions contrasts with its total failure under low lighting condition.
The primary independent variables that determine your customer’s imaging environment are— 1) the subject illumination and 2) the subject to
camera distance. The lens characteristics (f/# and focal length), determine the focus blur for a given subject distance. The lens aperture and shutter
speed will depend on the subject illumination. In general these variables will determine the amount of both lens and motion blur. At low illumination a flash is fired (if available). Knowing HOW, WHERE and HOW MANY should be an integral part of the design and development process. This knowledge will enable you to set appropriate specifications and measurement conditions to measure the performance of your camera under the conditions that your customer will experience.
In the past the ability to make these determinations was largely a closely held competency of major imaging companies such as Eastman Kodak and Polaroid, to name two. Image Phi brings this capability to your desktop.
Image Phi provides a simple, easy to use graphical user interface to examine large collections of digital images. The collected photospace data can be correlated with independent subjective evaluations of the images, providing a unique insight into the visual impact of the camera’s performance under the customer’s usage conditions.
Image
Phi enables the user to determine subject-camera distance from the
size of known objects relative to the image diagonal and subject
illumination from visual clues using a seven category scale of image
illumination.Image Phi can be used with minimal training. It displays the measured photospace distribution as a surface plot. For the purpose of further data processing and evaluation, the photospace data and the image by image characterization of subject-camera distance and subject illumination can be exported as a csv file.
Image Phi is offered with two hours of interactive support in a WebEx conference. An updated slide presentation first given at the IS&T Technologies for Digital Fulfillment Conference March 2007 will be included. Additional time will be made available for answering application specific questions.
Optimize your imaging device so that it delivers high quality images even under those difficult conditions that your customers often dare to use. Measure the performance of your imaging device for the conditions that your customer actually experiences. Purchase a copy of Image Phi now.
Recent Activities
Dirk Hertel and I have been examining upwards of 400 camera phone
images, using Image Phi to determine the photospace utilization of 5
popular camera phones ranging from VGA to 3 Megapixels in ‘resolution’.
We also did a subjective scaling of the perceived image quality. Since
each image is also characterized by its location in photospace we can
look at the correlation of image quality with the frequency with which
the cameras are used. We expect to present the results in a paper to be
given at the 2008 Electronic Imaging Conference in San Jose, CA. We will
give preview of the results here, emphasizing the importance of
understanding your customer’s experience, and the utility of Image
Phi in
obtaining these results.From the photospace distribution, we see that the majority of the camera phone images are taken under low lighting conditions and close distances. The subjective scaling of image quality reveals that the higher quality images are mostly taken under brightly illuminated conditions.
Bror Hultgren
Image Integration, Inc.
978.356.5975
bror.hultgren@i-2-q.com
ImagIntegration.com