Tif conversion

[Layton E Parham]

How do I convert 8 bit tif file to large jpeg? Larger than 3 meg!

[David Thomasson]

How do I convert 8 bit tif file to large jpeg? Larger than 3 meg!

If you have Photoshop, just open it, go to File > Save As, and choose jpeg for format.

[Layton E Parham]

David when i do that in Photoshop the largest file that i can make is 1.2meg?

[Alfred Forns]

Hi Layton I think all you can do is save as choose jpeg and the max quality (12) If you need to send the entire tiff file there are ways to do it !!!

[David Thomasson]

Hi Layton I think all you can do is save as choose jpeg and the max quality (12) If you need to send the entire tiff file there are ways to do it !!!

That's right. The size of the jpeg you end up with will depend on how much detail is in the image.

For example, if you have lots of clear blue sky or white snow -- i.e., lots of areas with practically no detail -- jpeg can compress those areas more efficiently
than it can compress details. So the image size will be smaller, even if you use the least amount of jpeg compression (level 12 in Photoshop).

[Layton E Parham]

They don't want a tif file they a jpeg 3meg or larger.

[David Thomasson]

They don't want a tif file they a jpeg 3meg or larger.

If level 12 won't give you 3 MB, you'll have to up-rez it ... but that could cost you some image quality.

[William Malacarne]

What size is the tif?

Bill

[Dug Threewitt]

They don't want a tif file they a jpeg 3meg or larger.
Who are "they"? I do a lot of large format printing at work and we never ask for jpeg @ a specific size. they may be saying larger than 3 meg to keep people from sending in web rez jpegs.
Dug

[Charles Glatzer]

You would need to start with approx a 16.7 meg file to save as a 3 meg jpeg at image option 12 maximum in Photoshop.
It sounds like their way of trying to make sure the file size is large enough for the intended purpose.

BTW- it seems strange they would not take a TIFF file.

Best,

Chas

[David Thomasson]

You would need to start with approx a 16.7 meg file to save as a 3 meg jpeg at image option 12 maximum in Photoshop.


No, that's a mistaken idea. There's no ratio between the size of the tif and the size of the resulting jpeg. The outcome depends on image details.

I could easily produce a 6 MB tif that yields a 3 MB jpeg (saved at level 12).

I could just as easily create a 55 MB tif that saves as a 2 MB jpeg (at level 12).

The difference in outcomes is mainly a function of how much detail is in the images.

[Jeff Donald]

Also the higher the ISO the larger the jpeg file, noise doesn't compress as well. The jpeg algorithm interprets noise as image detail.

[David Thomasson]

Also the higher the ISO the larger the jpeg file, noise doesn't compress as well. The jpeg algorithm interprets noise as image detail.

Exactly. Here's what happens with a large tif. #1 plain gray, #2 with noise added. Jpg's are saved at level 12.

http://img199.imageshack.us/img199/9655/tif1a.jpg

[Charles Glatzer]

David,

You can watch the remaining images on card go down simply by increasing the ISO.

I agree with your reply to my post ;)

Chas