Comments for picturation http://picturation.wordpress.com Miscellaneous, mostly technical, topics related to digital photography Thu, 01 Mar 2007 23:40:27 +0000 http://wordpress.com/ hourly 1 Comment on © Copyrighting Photographs by picturation http://picturation.wordpress.com/2006/03/30/copyrighting-photographs/#comment-70 picturation Thu, 01 Mar 2007 23:40:27 +0000 https://picturation.wordpress.com/2006/07/16/copyrighting-photographs/#comment-70 You're quite welcome. My article focuses mainly on US Copyright law, so you may want to take that into consideration. You’re quite welcome. My article focuses mainly on US Copyright law, so you may want to take that into consideration.

]]> Comment on © Copyrighting Photographs by steve heaton http://picturation.wordpress.com/2006/03/30/copyrighting-photographs/#comment-69 steve heaton Thu, 01 Mar 2007 16:43:05 +0000 https://picturation.wordpress.com/2006/07/16/copyrighting-photographs/#comment-69 thank u for the information it was most useful bye steve in northwest england. thank u for the information it was most useful
bye steve in northwest england.

]]> Comment on JPEG Compression — Devil or Angel? by picturation http://picturation.wordpress.com/2006/04/21/3/#comment-5 picturation Tue, 25 Apr 2006 00:46:47 +0000 https://picturation.wordpress.com/2006/04/20/3/#comment-5 Thanks, red dreamer Thanks, red dreamer

]]> Comment on JPEG Compression — Devil or Angel? by picturation http://picturation.wordpress.com/2006/04/21/3/#comment-4 picturation Tue, 25 Apr 2006 00:45:27 +0000 https://picturation.wordpress.com/2006/04/20/3/#comment-4 Hi Johno I agree. Changes to the image will result in a different JPEG compression and thus a different result. I intended to mention that in the article. But, as you also say, it's difficult to devise a way to test the extent of this effect. Years ago, before I learned about JPEG losses, I had an image I modified and saved many times. At the time I didn't noticed any harm done by this repeated change and save. But, I was less descriminating then. :) Hi Johno

I agree. Changes to the image will result in a different JPEG compression and thus a different result. I intended to mention that in the article. But, as you also say, it’s difficult to devise a way to test the extent of this effect.

Years ago, before I learned about JPEG losses, I had an image I modified and saved many times. At the time I didn’t noticed any harm done by this repeated change and save. But, I was less descriminating then. :)

]]> Comment on JPEG Compression — Devil or Angel? by .i dream in red. http://picturation.wordpress.com/2006/04/21/3/#comment-3 .i dream in red. Mon, 24 Apr 2006 23:16:56 +0000 https://picturation.wordpress.com/2006/04/20/3/#comment-3 Cool article. Thanks for the link on your site. I shall return the honor. =D Cool article. Thanks for the link on your site. I shall return the honor. =D

]]> Comment on JPEG Compression — Devil or Angel? by berk http://picturation.wordpress.com/2006/04/21/3/#comment-2 berk Mon, 24 Apr 2006 21:50:07 +0000 https://picturation.wordpress.com/2006/04/20/3/#comment-2 There are other ways to reduce file size without resorting to extreme JPEG compression (I define as 30+% compression). When I shoot, I start with the highest JPEG setting on my camera. I have the option of shooting RAW, but I don't know how to utilize that and it's not important for my hobbyist needs. I make a copy and archive the original. With the copy, I first reduce the DPI from 300 to 72 since I am only displaying on the web and not printing them. Next, I'll reduce the physical size of the image to about 1000 x whatever (gets it close to the resolution of my monitor). Just these two steps shaved a huge chunk off file size. I usually save the JPEG to 80-85%. The initial JPEGs start at 2-4 mb and end up at 150-250k. There are other ways to reduce file size without resorting to extreme JPEG compression (I define as 30+% compression). When I shoot, I start with the highest JPEG setting on my camera. I have the option of shooting RAW, but I don’t know how to utilize that and it’s not important for my hobbyist needs. I make a copy and archive the original. With the copy, I first reduce the DPI from 300 to 72 since I am only displaying on the web and not printing them. Next, I’ll reduce the physical size of the image to about 1000 x whatever (gets it close to the resolution of my monitor). Just these two steps shaved a huge chunk off file size. I usually save the JPEG to 80-85%. The initial JPEGs start at 2-4 mb and end up at 150-250k.

]]> Comment on JPEG Compression — Devil or Angel? by Johno http://picturation.wordpress.com/2006/04/21/3/#comment-1 Johno Mon, 24 Apr 2006 02:54:00 +0000 https://picturation.wordpress.com/2006/04/20/3/#comment-1 This all sounds pretty reasonable. The artifacts in JPEG come about from the approximations in fitting to particular combinations that are possible in JPEG with a certain number of pixels. Thus, using the same encoding algorithm again and again by opening and saving will result in exactly the same file. The uncertain thing is more when there are significant changes made to the image, such as doing a curves adjustment over the whole image or a rotation/scale. In that case it will have to be re-fitted to a different represenation, and is thus open to another round of degredation. It is a bit harder to do objective tests on such a scenario though. This all sounds pretty reasonable. The artifacts in JPEG come about from the approximations in fitting to particular combinations that are possible in JPEG with a certain number of pixels. Thus, using the same encoding algorithm again and again by opening and saving will result in exactly the same file. The uncertain thing is more when there are significant changes made to the image, such as doing a curves adjustment over the whole image or a rotation/scale. In that case it will have to be re-fitted to a different represenation, and is thus open to another round of degredation. It is a bit harder to do objective tests on such a scenario though.

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