gxseries Posted September 30, 2007 Report Share Posted September 30, 2007 I have got a couple of coins that seems to be very interesting and perhaps pretty scarce if not rare. I have come to a stage realizing that mere constrasting is not enough and I think I will need some help with noise removal and differentation. I do wish that I have a 10mp digital camera or more but that is not an option at the moment I do remember doing something like this on a MathCad but I don't have the software any longer. Would photoshop have a similar function to this? (or is this topic even making any sense to anyone? ) Or alteratively my last option is to pick up a cheap stereo microscope but that too sounds very expensive. Link to comment Share on other sites More sharing options...
just carl Posted September 30, 2007 Report Share Posted September 30, 2007 You lost me. Exactly what has noise got to do with taking a photo? What differentiation are you talking about? As to a 10 Mega Pixel camera, why. You could use a thousand Meg camera, if one existed, and still have to reduce it for posting on any web site. If your just attempting to take a photo of a coin, there are numerous web sites on how to take coin photos out there. Also, many cheap or free photo programs available by just downloading. For example Picasa is free. I have abaout 5 or more photo programs and one is photoshop and still never even opened it. www.coppercoins.com has a how to takd photo section. Also, a place called Table Top Studio, coin photography techniques. You don't need a fantastic camera, microscope, etc., you check out the many options available. Link to comment Share on other sites More sharing options...
GDJMSP Posted September 30, 2007 Report Share Posted September 30, 2007 First of all, what did you use to take the pics and at what resolution ? Secondly, what exactly are you hoping to see in the pics - more detail, color, luster - what ? Link to comment Share on other sites More sharing options...
gxseries Posted September 30, 2007 Author Report Share Posted September 30, 2007 Thanks carl and doug, it's actually not the resolution or detail that is tricky but more to do that the coin itself is corroded that makes it harder to visualize. To be more honest, it's the corrosive nature of the coin that makes it more difficult to visualize. For example: This was shot with a 5mp Ricoh digital camera but at ISO 200 - I don't have enough lighting. I should consider lowering it down to ISO 64 which will help with the noise issue. My idea of image differentiation is to be more selective of how I can pick certain aspects of the design and have a control over to constrast. Constrast might help a bit but it is too generic for what I am trying to exploit. The thing is, I did remember doing something like with on Matlab but unfortunately I don't have the software I was kind of hoping someone in this forum would have access to it and help me play around with the images that I have. Link to comment Share on other sites More sharing options...
GDJMSP Posted October 1, 2007 Report Share Posted October 1, 2007 Well after looking at that I assume that what you after is a computer program that can take poor images and enhance them into recognizable objects - kind of like the computers in the movies where they say - "now enhance that". If so, sorry pal - can;t help ya with that. However, after looking at your image, if I had to guess I'd have to guess that it was a counterfeit lion dollar. Link to comment Share on other sites More sharing options...
De Orc Posted October 1, 2007 Report Share Posted October 1, 2007 Looks more like a flying horse to me or at least one with wings LOL Good luck on finding a programe Link to comment Share on other sites More sharing options...
gxseries Posted October 1, 2007 Author Report Share Posted October 1, 2007 It's actually this coin here GDJMSP, a kopek coin: While I am relatively happy with my camera, I realized that there is a need to go further. Mind you, it might seem like a totally corroded copper coin which is almost worth it's metal value but this particular coin is perhaps more rare than most people who might realize. This seems to be an overstriked coin (I did orientiate it to the underlying crown) but unfortunately I haven't found a systematic method of dealing with such coins. Yes, I might be able to sketch it on paper but it is a lot more trickier than what I expect it to be. Link to comment Share on other sites More sharing options...
josemartins Posted October 1, 2007 Report Share Posted October 1, 2007 I think GX is talking about some type of edge detection filter, but there is so many noise in there that it would be better to actually blur the image a bit (or a lot). I have the GIMP at home and i think it might be able to do this. Jose Link to comment Share on other sites More sharing options...
GDJMSP Posted October 2, 2007 Report Share Posted October 2, 2007 Ahhhhh what a difference - lions, horses - they're almost the same thing Knowing you I figured it had to do with you trying to see an over-strike. But Boy Howdy ! - trying to figure that one out is gonna be tough. But of anybody can do it, it'll probably be you Link to comment Share on other sites More sharing options...
just carl Posted October 2, 2007 Report Share Posted October 2, 2007 Noting the shadowing I'd say you could do a lot better if you took the photos outdoors. On a bright sunny day, but not in direct sunlight, you would get a much better quantity of natural lighting and if in the proper location, no shadows. Digital cameras always work better with a large amount of light and in daylight that is there. I use several digital cameras with different MegPixels and different settings and most always come out the best on a bright sunny day. Also, placing the coin on a dark background will force the camera to consentrate on the coin instead of the background. Try it. Nothing to loose. Link to comment Share on other sites More sharing options...
gxseries Posted October 3, 2007 Author Report Share Posted October 3, 2007 Thanks Carl, most definately there is lighting issue in most of the coins that I take. Should always take good note of it. This is what I am thinking of doing but I guess it is beyond normal standards: http://lakdiva.org/coins/ruhuna/ruhuna_grains_cu.html http://hasyweb.desy.de/science/annual_repo...ib/48/11472.pdf http://www.sciencedirect.com/science?_ob=A...cd9bc335731053c http://www.sciencedirect.com/science?_ob=A...942fb8b3ce61ab0 Oh geez, I did forget that I have an account at ScienceDirect, will have to download the articles Link to comment Share on other sites More sharing options...
just carl Posted October 10, 2007 Report Share Posted October 10, 2007 Starting to sound like your getting carried away with a scientific factor about coinage. It is actually supposed to be a hobby that is interesting, possibly investing, educational and primarily FUN. hope your not missing out on the FUN part. Link to comment Share on other sites More sharing options...
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