Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: I SAY AGAIN -- Re: ADMIN: attachments: pdf vs jpg and others
    From: Brad Morris
    Date: 2013 Apr 23, 19:14 -0400

    Hi Alan

    Frank and Don have explained it properly.  The JPEG image may be saved at levels, trading image quality for size.  The sharper and crisper the image quality (like crisp readable text versus fuzzy edges) the larger the file size.

    Given a fixed jpeg, wrapping in a PDF container just adds bytes. There is no savings when the fixed JPEG is wrapped in a PDF You use a PDF when you want to control the entire package presentation, text, images, pagination & etc.  Its fixed in presentation and therefore much harder (for the average user) to manipulate or change.

    When Kermit, who I have lots of respect and admiration for, saved the scanned image as a PDF, it MUST have been at lower quality JPEG.  The sum of the low quality JPEG plus the PDF wrapper bytes was less than a high quality JPEG image alone.  His data point is correct but not in detail.  If we were to unwrap his PDF, to extract the JPEG from it (which can be done, albeit by non standard users), we would find that the JPEG is smaller in size and therefore, lower in quality.  Think of it as a false horizon under the moon.  It can trick even the best.

    Its a judgement call as to what quality you want.  Consider this.  The latest iPad, with the so called retina display, has pixels smaller than the naked eye can resolve.  The crowd is wow'd.  Text is super crisp.  But the much cheaper Kindle has perfectly readable text.  Which one is good for your purposes?  I'd say, judgement call.

    I've been around the software & computer field since 1969.  So this is not just my opinion, but rather a technical assessment. 

    There are no sides to take here.


    On Apr 23, 2013 6:12 PM, "Alan S" <alan202---.net> wrote:

    I wonder why jpg takes up the additional time and space, compared with pdf's as Kwermit describes. Possibly someone who understands computer communication better than I, that likely comes to a very large number of people, could explain.

    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    View and reply to this message: http://fer3.com/arc/m2.aspx?i=123667

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site