|
Title: Post processing using DPP Post by: piyush on March 01, 2009, 09:38:10 PM Why simple correction in DPP like color correction/sharpness increases the file size to double or triple? I have noticed same thing in Picasa also. Am i doing some thing wrong? Not sure but all the files were 1.5 to 2 mb and after batch processing, it becomes 3 to 4 mb and some of them become 6 mb too.
Title: Re: Post processing using DPP Post by: Bob Atkins on March 02, 2009, 10:08:22 AM I guess you are taking about JPEG files here. JPEG is a compressed format. When you open the file it's uncompressed so you can work on it and when you save it it's compressed again. The compression is lossy and the harder you compress (i.e. the smaller you make the file), the more loss you have.
The simple explanation is that the files you are opening are more highly compressed than the files that DPP saves. DPP has a default compression, but you can change it if you want to. Also sharpening will slightly increase the amount of detail in a file, which means it will be slightly larger at any given degree of compression. However it wouldn't double or triple the file size, so I suspect it's simply a matter of different degrees of compression. Title: Re: Post processing using DPP Post by: KeithB on March 02, 2009, 10:35:51 AM Or if DPP is reading a RAW and outputing a TIFF, there may be a large increase in filesize since the RAW file only has a single "chunk" of pixel data, while the TIFF has 3 one each for R, G, B
Title: Re: Post processing using DPP Post by: Bob Atkins on March 02, 2009, 12:19:20 PM True, but looking at the file sizes, its not likely that TIFFs are involved. The numbers (2-6MB) suggest JPEGs.
Title: Re: Post processing using DPP Post by: piyush on March 02, 2009, 09:00:36 PM Oh yes, That's true Bob. I am using Large-Normal setting on Canon 400D (XTi) which comes to somewhere around 2 mb for each of the files. I got it. Thanks for the explanation. I will look into the compression in DPP. Thanks again.
|