Jpeg images use compression techniques that summarise close-up detail (to get the file size down). When you save an image in Photoshop it has to re-calculate this on the fly. If you use photoshop to rotate your image it will technically change the image and therefore it will recalculate the compression and therefore the quality could go down by a fraction of a percent. If you keep making changes to the same jpeg in photoshop the quality will gradually diminish.
If you use a different program to rotate your images that does not actually open them (I Use Canon Zoom Browser) it just works on the whole file. The speed it takes is mainly down to your processor and image size (to some extent the software). Zoom browser on my machine takes about 5 seconds to rotate a 3000x2000 pixel jpeg. Photoshop on my machine takes 10 seconds to do the same thing. But then you have to add in the time to open it and save it again as well which is not necessary if you do not open the image in the first place. OK? Nathan. Nathan Gaydhani BSc Photographic & Digital Imaging nathan - photography and digital imaging The Studio, 53 High Street, Sutton Village Bedfordshire SG19 2NF t. 01767 261 952 www.nathan.org.uk -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ellie Kennard Sent: 05 August 2003 12:46 To: [EMAIL PROTECTED] Subject: [PRODIG] Rotating TIFFS (was JPEGs) At risk of getting caught in the crossfire here, would someone tell me if rotating another file format in PS (such as TIFF or PSD) will degrade the file? Surely the speed at which an image is rotated is affected by three factors: size of file available resources and speed of computer efficiency of the software I have never taken over two minutes to rotate an image of that small size, I am certain. I am keen now to go and test it out. Respectfully, Ellie -- Ellie Kennard Innovative Imaging Studio http://www.iiStudio.com =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
