Confused about file size versus document size in memory

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The file size of a document is given in 'Bridge' metadata, expressed in MB (assume megabyte).

THE SAME NUMBER can also be obtained in Photoshop 'image' > 'image size' and is also in the bottom of the image window expressed this time in both cases as 'M' (units ?).

Hovering the mouse pointer over the Photoshop 'image size' box however causes a temporary text window to appear which reads "Describes the document size in pixels".

Isn't a byte the equivaqlent of three pixels (RGB) ?............ so surely there is an error here in the way these things are expressed in Photoshop.

Can someone please explain this for me, or can Photoshop please correct this.
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Ikon Ormerod

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Posted 6 years ago

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Chris Cox

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No, those are not the same number.

Bridge is showing you the FILE size.
Photoshop is showing you the size of the flat image data, without any compression -- and that has little to do with the size of a file on disk.
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Ikon Ormerod

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Thanks for your help.

I realised after I posted the question that tif files show the same number but jpegs show different numbers as you say.

Thanks again

regards

Brian