Truman Prevatt

Truman Prevatt

Lives in United States Brooksville USA, United States
Works as a Mathematical Physicist
Joined on Dec 24, 2001

Truman Prevatt's recent activity

  • Yes all print drivers will map the pixel array to their own array for laying down ink. Epson uses multiples of 1440 for their basic array. However, that also can be confusing since printers use a ...
  • Folks what is being missed in this whole goat rope is the enlargement ratio to the final print.  100 MP 4x5 sensor will be projected 2 times for an 8x10 print and 4 times for a 16x20 print.  A 100 ...
  • In many RF systems, the signal is significantly oversampled with an AA filter with a very gentle roll off.  That means the anti-aliasing filter can be designed so that the phase is linear over the ...
  • The yahoo group, DigitalBlackandWhiteThePrint is an excellent place to start.  There is a wealth of information in the group and several of the participants are actively involving in developing ...
  • Epson can support it. However, I don't know how much their large format printers cost.
  • Rick, that is pretty much it.  In reality if you are using the epson printer driver, you are better off to select a size and 360 DPI and let the printer to the rest.  Of course there are other ...
  • The Epson's are based on a sub-multiple of 1440, e.g.. 180 360, 720 or 1440 as native resolutions and will handle the interpolation for printing to the native resolution. Personally - at least for ...
  • Replied in Will ... ?
    A half way decent technical discussion of resampling including bi-cubic. http://eeweb.poly.edu/~yao/EL5123/lecture8_sampling.pdf
  • Replied in Will ... ?
    Roland, I'm not sure what you are trying to say is getting through.  When one down samples, unless that process is proceeded by a digital low filter that limits the spatial frequency response to ...
  • A localized beam spreader or "defuser" as you call it is an interesting option.  Within the footprint of the beam spreader, multiple pixels pick up the three colors (RGB) and amplitude ...
  • The MDS is a measure of a receive system sensitivity. In reality a EO sensor is a multichannel receiver since it converts radiation into a series electrical signals. In reality it is no different ...
  • Not only are their practical issues with significant oversampling (large data files, long read times, large buffers required, more detector electronics and ADC electronics equals more noise, ...
  • Of course they didn't check then.  But now in the US it is common to asked for an picture ID to validate you are the user of the card.  My card comes from a credit union which requires a "special" ...
  • Yes. Normally dB means related to noise floor.  For this experiment define minimal detectable signal as 3dB SNR.  The minimal detectable signal is somewhat arbitrary but it is a bit easier to work ...
  • https://en.wikipedia.org/wiki/Film_speed#Measurements_and_calculations The equations that go into the ISO rating involve "H" the luminous exposure (in lux seconds) at the sensor, H=qLt/(N^2), L is ...
  • Minimal detectable signal relates to the current out of the detector vs. the noise.  The ISO is related to the light energy onto the face of the sensor array required to produce the minimal ...
  • An optical sensor has a base sensitivity (as does film).  That sensitivity is the light energy associated with the minimal detectable signal.  In electronic components that is normally specified ...
  • Every unencrypted electronic transfer is vulnerable. E-commerce over the web is encrypted - which provides a degree of safety. The problem with chip and pin - is the pin part. Today people are ...
  • The concept behind RFID chips is pretty simple. They shore identification information on a chip which is little more than a small amount of memory, a transmitter and antenna which is powered and ...
  • Taking this graph along with the other graph that tracks production since 1947 what you see is digital cameras were a technology advancement that generated a bubble in the market. Bubbles are not ...
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