Photoshop 7 3MB JPEG is 30MB in Pixel Dimensions

A 3MB (on disk) jpg image was produced by a camera from a 30MB TIF uncompressed file. In Pshop, when Image Resizing, the pixel dimension displayed is 30MB for that 3MB file.

I was hoping to upsize the jpg to 34MB by changing the image size and monitoring the pixel dimensions, but that doesn't work.

Explanations/suggestions/comments appreciated.

Michael

Michael,

The 'pixel dimensions' file size shown in Photoshop's Image Size dialog is a no-compression reading.

Because the JPEG format can be written with varying degrees of compression, the Image Size reading and the size of a saved JPEG are not necessarily directly related.

When the file is opened by Photoshop, what you see is no longer a JPEG, it is a virtual PSD file.

The file size shown reflects the actual image size, without compression factored in.

<http://www.faqs.org/faqs/jpeg-faq/part1/>