Image Processing

Wacom Intuos 4

Posted in Equipment, Image Processing on August 29th, 2010 by Krishnan V – Be the first to comment

I recently got hold of a pen tablet the Wacom Intuos 4 ( Medium Sized which is the PTK-640)

Definitely much better than using a mouse. It will take a little getting used to. For the ease of use, it will be worth it.

For those looking for one, even the smaller size (6×4 inch active area the PTK-440) will do just fine.

Post Processing steps

Posted in Image Processing on June 23rd, 2010 by Krishnan V – Be the first to comment

Well here are my basic post processing steps that I follow. I use the Nikon software Nikon Capture NX2. But you can use the same flow in pretty much any image processing software.

1. Open RAW image in NX .

2. Turn sharpening OFF

3.  Image at 100% . Adjust White Balance. Then I add a grey point and chose a spot on the  image which should be neutral grey in that light.

4. Adjust Exposure ( Exposure Compensation )

5. Neutralise Gamma :

a) New Step

b) Light > Levels & Curves

c) Press Right Top histo button to make histo “live”( Capture NX) { Left most button in Capture NX2 }

d) Select Red channel

e) Bring left bottom slider to beginning of  histogram’s left side

f) Bring middle slider back to 128 mark.

Gamma_Composite

g) Repeat steps e) & f) for Green & Blue channels ( Histo should be “live” when you do )

h)  Repeat e) & f)  for RGB channel. But you can adjust centre slider to taste in this step.

i) Then I chose to add overall warmth to the image

j) Next  I added yet another control point and punched  up  the  contrast.

6.  Add mild sharpening to overcome the blurring caused by the anti-aliasing filter. ( This is not output sharpening).  For these unsharp mask, values I typically use for D2X ( 50, 5,  4) and D3 ( 35, 7, 3).  Ofcourse,  you can vary these to taste but,  high values here are not needed !

7.  Save RAW file.

You could use the same steps above for jpeg images. But, you will not be able to turn sharpening off or directly adjust white balance. What you can do here is , view image at 100%. Then,  use the white, black & neutral points. The rest of the steps are the same.

Tiger-Composite2
Tiger-Composite1

Note on colour casts: Long light (very early morning & evening)  will have some cast and,  even a pure grey subject will reflect that warmth.

Capture NX Tips >

http://support.nikonusa.com/app/answers/detail/a_id/14234

http://nikoneurope-en.custhelp.com/app/answers/detail/a_id/22992

http://www.capturenx.com/en/lessons/lessons/index.html

http://www.nx101.com

You can also use the following technique to improve a flat image.

1. Convert image to LAB

2. Curves layer

3. “a” channel , Bring bottom slider inwards and,  the top slider inwards as well by the same amount.

4. Do the same for the “b” channel

5. Tweak the lightness channel to taste.

Details with screen shots in this thread .

Would love to know on how you found this for your processing.

A hand at some simple macro with processing

Posted in Image Processing on August 23rd, 2009 by Krishnan V – Be the first to comment

Today, I tried something which I usually don’t .

Regular flower macros but I spun them a lil in post processing.

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And here is the yellow rose :-)

20090823_173540

Geotagging Images

Posted in Image Processing on February 9th, 2009 by Krishnan V – 11 Comments

I just got back from a trip to Manas & Kaziranga National Parks. One of the things I wanted to try was “Geotagging“. Geotagging helps to write the exact location where the pic was shot, into the EXIF of the pic itself. The software also creates a “.kml” file which will help view the route along with, the exact point on the track where the particular photograph was taken.

I took along a Garmin Etrex Legend GPS and also this is where it gets more interesting, a Nokia 5800 Expressmusic along with a Nokia LD-4W bluetooth GPS. Although the Nokia 5800 Expressmusic has a built in GPS, I took along an external GPS since that is so much more flexible for my application. Besides, the Nokia LD-4W is only a few tens of grams in weight and, smaller than a credit card :-) . So its hardly any trouble carrying it.

I set the Garmin to “Log Track mode”. For the Nokia, here is what I did. Since the Nokia application, “Sportstracker” was at that time not available for the Nokia 5800 (Sportstracker for 5800 EM) , I downloaded another software called @Trip v1.01 . This is a simple phone app that creates a log of the GPS track and writes to a file. You can also use similar apps like GPSED. It will also geotag pics clicked by that phone. Besides you can use the bluetooth GPS + gps app on any non-gps phone.
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A bit of Gaussian Blur

Posted in Image Processing on August 15th, 2008 by Krishnan V – 1 Comment

I worked on this pic from Tadoba, so as to blur everything but, the four spotted owlets.

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And here is another which is not as much blurred.

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