TIFF or JPEG??

[RES08]

Hello, im extremely new to using imagej and i was just wondering if it is better to use images saved as TIFFs or JPEG? At the minute the images im using are saved as JPEGs on the camera and computer, however before using them in imageJ i save them as TIFFs!

Thanks
Rachael

[lechristophe]

Hello,

JPEG is usually compressed with a loss of information. TIFF is usually non
compressed or compressed with lossless algorithms. So my advice would be to
use TIFF rather than JPEG, but it would be better to start with an acquired
TIFF/RAW rather than a JPEG.

Christophe

On Fri, Mar 21, 2008 at 5:58 PM, RES08 <[hidden email]> wrote:

> Hello, im extremely new to using imagej and i was just wondering if it is
> better to use images saved as TIFFs or JPEG? At the minute the images im
> using are saved as JPEGs on the camera and computer, however before using
> them in imageJ i save them as TIFFs!
>
> Thanks
> Rachael
> --
> View this message in context:
> http://www.nabble.com/TIFF-or-JPEG---tp16202185p16202185.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>

[David Hovis]

On Mar 21, 2008, at 12:58 PM, RES08 wrote:
>
> Hello, im extremely new to using imagej and i was just wondering if  
> it is
> better to use images saved as TIFFs or JPEG? At the minute the  
> images im
> using are saved as JPEGs on the camera and computer, however before  
> using
> them in imageJ i save them as TIFFs!

JPEG introduces artifacts into your image.  Converting from JPEG back  
to TIFF does not reverse the artifacts.  For a scientific image, TIFF  
is preferable.

--David


----------------------------------------
David Hovis
Senior Research Associate
Department of Materials Science
Case Western Reserve University
[hidden email]

[Gabriel Landini]

On Friday 21 March 2008, RES08 wrote:
> Hello, im extremely new to using imagej and i was just wondering if it is
> better to use images saved as TIFFs or JPEG? At the minute the images im
> using are saved as JPEGs on the camera and computer, however before using
> them in imageJ i save them as TIFFs!

Point 4 in here tells you why one should not use jpegs in image analysis:
http://imagejdocu.tudor.lu/imagej-documentation-wiki/faq/what-should-i-do-before-start-using-imagej-in-my-project

If you already have jpegs, your images are already lossy and the only solution
is to grab images again.

Cheers

Gabriel

[Kenneth Sloan-2]

On Mar 21, 2008, at 12:36 PM, Gabriel Landini wrote:

> On Friday 21 March 2008, RES08 wrote:
>> Hello, im extremely new to using imagej and i was just wondering  
>> if it is
>> better to use images saved as TIFFs or JPEG? At the minute the  
>> images im
>> using are saved as JPEGs on the camera and computer, however  
>> before using
>> them in imageJ i save them as TIFFs!
>
> Point 4 in here tells you why one should not use jpegs in image  
> analysis:
> http://imagejdocu.tudor.lu/imagej-documentation-wiki/faq/what- 
> should-i-do-before-start-using-imagej-in-my-project
>
> If you already have jpegs, your images are already lossy and the  
> only solution
> is to grab images again.
>
> Cheers
>
> Gabriel

This is conventional wisdom among those of us who endured low  
resolution, low quality images of the past.  Without knowing more  
about the application, the imaging setup, and the objects being  
imaged, it's impossible to say.

As a general rule, if you are treating your images as collections of  
pixels which happen to be packed together in a fairly arbitrary way,  
then tiff will be better than jpeg.  If, on the other hand, you are  
analyzing large scale structures, then jpeg *may* be appropriate.

--
Kenneth Sloan                                          
[hidden email]
Computer and Information Sciences                        [phone]
University of Alabama at Birmingham              FAX [phone]
Birmingham, AL 35294-1170                http://KennethRSloan.com/

[Joel Sheffield]

If you are furtunate enough to own or have access to Wilhelm Burger
and Mark Burge's excellent text on Digital Image Processing (Springer
Verlag, 2007), you will find a remarkably clear discussion about the
advantages and problems with the JPEG format starting on page 17.

I am not a programmer, and yet I found the text remarkably lucid,
even to a non-expert.

Joel


Date sent:       Fri, 21 Mar 2008 13:31:19 -0500
Send reply to:   ImageJ Interest Group <[hidden email]>
From:           Kenneth Sloan <[hidden email]>
Subject:         Re: TIFF or JPEG??
To:             [hidden email]

> On Mar 21, 2008, at 12:36 PM, Gabriel Landini wrote:
> > On Friday 21 March 2008, RES08 wrote:
> >> Hello, im extremely new to using imagej and i was just wondering  
> >> if it is
> >> better to use images saved as TIFFs or JPEG? At the minute the  
> >> images im
> >> using are saved as JPEGs on the camera and computer, however  
> >> before using
> >> them in imageJ i save them as TIFFs!
> >
> > Point 4 in here tells you why one should not use jpegs in image  
> > analysis:
> > http://imagejdocu.tudor.lu/imagej-documentation-wiki/faq/what- 
> > should-i-do-before-start-using-imagej-in-my-project
> >
> > If you already have jpegs, your images are already lossy and the  
> > only solution
> > is to grab images again.
> >
> > Cheers
> >
> > Gabriel
>
> This is conventional wisdom among those of us who endured low  
> resolution, low quality images of the past.  Without knowing more  
> about the application, the imaging setup, and the objects being  
> imaged, it's impossible to say.
>
> As a general rule, if you are treating your images as collections of  
> pixels which happen to be packed together in a fairly arbitrary way,  
> then tiff will be better than jpeg.  If, on the other hand, you are  
> analyzing large scale structures, then jpeg *may* be appropriate.
>
> --
> Kenneth Sloan                                          
> [hidden email]
> Computer and Information Sciences                        [phone]
> University of Alabama at Birmingham              FAX [phone]
> Birmingham, AL 35294-1170                http://KennethRSloan.com/

--
Joel B. Sheffield, Ph.D.
Biology Department, Temple University
1900 North 12th Street
Philadelphia, PA 19122
[hidden email]  
[phone], fax [phone]
http://astro.temple.edu/~jbs

[RES08]

My images are of photoquadrats from rocky shores, so i'm using imagej to analyse percentage cover of species! Thanks for all the help, its very much appreciated!!

Thanks again, Rachael

[Joachim Wesner]

ImageJ Interest Group <[hidden email]> schrieb am 21.03.2008 17:58:55:

> Hello, im extremely new to using imagej and i was just wondering if it is
> better to use images saved as TIFFs or JPEG? At the minute the images im
> using are saved as JPEGs on the camera and computer, however before using
> them in imageJ i save them as TIFFs!
>

If the original data already are in JPEG you neither gain nor loose
anything
when further converting those to TIFF for processing.

JPEG reading **should** be independent of the reader used, it should
neither
introduce or remove extra artefacts (as sometimes is the case with MPEG),
small differences between applications might exist, due to rounding errors.

I do not know how "good" the ImageJ JPEG reader code is, there was an issue
that
the *writer* code seemed a bit too lossy, even at the highest quality
setting.

Joachim


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