Home › Forums › TWAIN Classic › compression from scanner VS compression in app
- This topic has 2 replies, 3 voices, and was last updated 16 years, 11 months ago by MarkM.
- AuthorPosts
Hi, I am new to TWAIN
I was wondering, is getting the image in jpeg format directlly from the scanner is a much better solution than getting the image in bitmap and compress the image in jpeg in the application?Jpeg compression from the scanner is better than compressing the file yourself in your app? (ratio quality/size is better?)
Tnx!
seems like this hangs somewhat on how well the vendor does their job and how well you do yours. But if everything else is equal it seems to me that the odds are in the vendors favor as they could be doing this in hardware (ok they probably aren’t, but they could).
Then you have to think about how consistant you want stuff to be between vendors in your app. If you handle the compression yourself outside of twain and just ask the vendor for a bmp you should be able to get pretty consistant results where if you always rely on the vendor then your mileage will probably vary – especially when you hit a vendor that doesn’t provide for compression at all….
Thought I’d toss in my two cents on this one…
For low end scanners (and to me low end is 40 pages per minute or slower), it’s likely that any jpeg compression will be occuring in the host PC, whether it’s done by the application or the driver. That’s a matter of cost, and because jpeg is very well defined it doesn’t matter from an image quality point where the compression occurs.
For faster scanners the bottleneck is I/O, and in that case jpeg compressed images coming over the wire may be the only way to maintain the speed of the scanner….
- AuthorPosts