Tuesday, April 26, 2011

Kindle Pictures Feature. .2 Free Tools that Convert Images to Kindle format.

Kindle 3 and Kindle 2 with same screen-sleeper
  (Windows utilities, though the first one can be done via a website.)

(Update/Correction: I fixed an E-nki site link to bring people to the right site!).

As Kindle owners learn quickly, Kindle screensavers (really, screensleepers) are not officially replaceable by our own images (unless one uses a 'hack' and that can be problematical in a few ways although some find it worth doing...and re-doing with each Kindle software upgrade).

  I don't recommend it, and only the computer savvy should tackle it; even then, there are disclaimers by the utility makers that your warranty can be voided if a problem occurs during installation.  It's not super-difficult but no one is going to be responsible for anything going wrong on it, so I don't get into the details.  You can always google kindle screensaver hack to see what's involved.  I personally don't think it's worth it.

 And now the latest Kindle (with Special Offers and ads) shows Amazon had a specific reason for not offering "screensavers" that could be customized by the Kindle user.

It'd be nice if Amazon were to offer customizable screensleepers for their higher-cost Kindles without ads, at some point. (The sad dream that never dies.)

Your Photos on your Kindle in the Pictures Folder - a Kindle Feature
In the meantime, Kindle owners CAN put favorite photos or illustrations on the Kindle in a special Pictures folder, and I've found that many don't know this is possible.

  The instructions for this are in the Kindle User's Guide (which is placed by Amazon on each Kindle during first wireless sessions and is also available for your computer in PDF format -- see Kindle User Guides at the Amazon help pages).

  Remember that Kindle books or files can be Searched for words like "pictures" and sometimes that makes it easier to find a feature.

  A Kindle customer posted step-by-step instructions at the Amazon Kindle forums.  In reply to an earlier post on Feb 9, Anthony Hansen wrote (slightly modified) :
' If you would like to add photos to your Kindle 2, it's pretty easy to do.  Here are a few short steps to getting some pictures onto your Kindle.

1. Connect your Kindle to your computer with the Kindle USB cable.
2. Go to the file folders for your Kindle on the computer and add a new folder called `pictures' (without the quotes).
3. Within the new `pictures' folder that you just created, create other folders which will be used to store your pictures.  The names of these sub-folders should describe what type of pictures will go into the folders.  These sub-folder names are what you will see on the Kindle's `Home' page and are the photo albums that you will put pictures into.
4. Add pictures into the newly created sub-folders (albums).
5. Safely remove your Kindle from the computer.
6. Go to the `Home' page on your Kindle and press Alt & Z keys together (alt-z) to see the photo albums.
7. Go down to the photo album that you want to view using the 5-way button [or the Kindle-1's mercury-like rolling column-cursor] and then select the album to view the pictures.

That's it.  This should take no longer than five minutes to do depending on the number of pictures [you're] adding '


This is a nicely easy-to-use tool that converts almost any image you have (size does not matter much) to a Kindle-compatible black & white version in the right size and orientation for the Kindle display.  It works for 6" Kindles and the 9.7" Kindle DX's.

It does convert 'up' to larger sizes rather well, to my surprise, but sharpness and clarity will be more likely when you send a larger photo to convert 'down' (and something to remember if doing this for the larger-screen DX).

  It's also very fast, even using the method as seen in the image of the webpage above, uploading a photo to the website for conversion -- probably the way to do it for Macs.

  But the link below the uploaded filename field is for a download of the executable (a Windows file), which means you can have the tool on your Windows computer and do it without uploading the file to the webpage.

  If you decide to try it, let us know how that works for you.

I haven't had a chance to try this one.  E-nki describes it this way:

"E-nki is an image processor designed for latest Kindle.
  "It converts common image documents (JPEG, PNG, GIF, BMP) into optimized PNG files for e-ink displays, and more important, you can convert your compressed archives directly. (CBR and CBZ too!)

  There is also a link to the FAQ, which does answer questions not addressed on the main page.  E-nki is a downloadable file and there's no web-style conversion tool.

On what, specifically, the utility does:
1) Converts pictures to grayscale
2) Tries to remove white borders
3) Resizes pictures while maintaining the aspect ratio
4) Rotates the pictures

  Author E-nki is on vacation but checking mail, so you can send questions to the e-mail address given at the webpage.

  As mentioned, I haven't tried it.  So, it's not a recommendation but a suggestion.  If you can, let us know (in the Comments area) what you think if you try one or both of the tools mentioned here.
  The feedback and useful info (and some raves) on SendtoReader (to Kindle) were very helpful.

As ever, when you enjoy and regularly use a free utility, support the software developer with donations if they feature a donation-method.  That tends to support improving the product and time giving user support.  That includes the popular Instapaper, which itself is used in a few other tools.

Kindle 3's   (UK: Kindle 3's),   K3 Special, $114   DX Graphite

Check often: Temporarily-free late-listed non-classics or recently published ones
  Guide to finding Free Kindle books and Sources.  Top 100 free bestsellers.
UK-Only: recently published non-classics, bestsellers, or £5 Max ones
    Also, UK customers should see the UK store's Top 100 free bestsellers. Below are ways to Share this post if you'd like others to see it.
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  1. i want the screensaver to freeze on the image oor text I'm looking at right now, not random images

  2. The '/pictures' folder is optional. You can put pictures in subfolders of '/documents' and it will work the same way.

    But I prefer to package image files in a .zip archive and drop that into '/documents'. Kindle will open these and launch the image viewer just as if they were in a folder. The advantages are some space savings and the ability to delete the .zip file on the Home screen. By contrast, deleting a picture folder item does not remove any files from your Kindle - just temporarily removes the item from Home screen.

    Another option is to package images in a PDF file. Then you have access to the PDF viewer features: annotation, contrast adjustment, pan/zoom, save viewing location, page numbers, etc.

    I've played with several of these utilities, but find they are more fuss than they are worth, at least in terms of my requirements. Kindle's default scaling and greyscale conversion seems 'good enough' for me. And in the end, the image viewer is nothing to write home about. I guess the remarkable thing is that Kindle is able to do it at all, like the proverbial talking dog.

  3. Tom, thanks for that info. Probably best for people to use the organization (via pictures folder) suggested by Amazon in any case and not throw pics into documents (for our own sakes).

    That's very interesting about the zip file being recognized that way. Which models have you tried it on? Very nice, especially since we can easily use file mgrs to remove individual items from a zip file and that is better for organization as well as saving space and eyes in trying to make out what is where.

    As for deleting folder items, maybe you mean something else, but I often delete gifs and they are deleted from the Kindle, not just the home screen.

    Thanks for PDF idea -- I avoid these as I like to fill my screen with a pic and not load a 'book' of images, not liking the 'speed' (not). "-) and replace individual ones from time to time.
    Personally, I don't like the Kindle's default handling of screen images at all. I've had to rework them to get them to show the way I want. With the utilities it's instantaneously good. I may want more contrast, in which case I add some and then replace the other copy.

    Right that it's good it can be done at all but especially when there are pics I just want to see on it when I want. You have to add a lot of contrast to have them look decent on the Kindle...

    Do you have a preference so far between the Kindle image converter tool and the E-nki one ? besides batch handling?

  4. Hi Andrys! I am one of your regular readers so I wanted to start by giving you a big thanks.

    There is still apparently a problem with the link on your website which links your blog to the Kindle Image Converter.

    I am on your website on 4/28/11 at 1:55 PM local NYC time. On the top of your webpage there is a big red note saying that you updated the link for the Kindle Image Converter. But when I just clicked on the link I received a error message that Firefox could not find the link.

    Again thanks for all the good work on your blog! :)

  5. dorachild,
    Thanks for the regular reading!

    The update was re the E-nki links -- that is also an Image Converter.

    However, the Kindle Image Converter one works for me. Did you refresh your browser? I think that reddit.com topic on this showed some problems for some people with that site because it's a cheap free site, the author said.

    I'll go see if there are workarounds for those who have problems with it.

    Thanks for the alert.

  6. Andrys,

    The ability to view images in .zip/.cbz has been in every Kindle, or at least those since K2. You'll note that Kindle creates a '.manga' sidecar file to store viewing position. Obviously whoever designed the image viewer feature intended to use it for viewing manga image files, which are often stored in .zip or .cbz files. Another clue is the 'Anchor to Top Right/Left' Menu option in the image viewer, since viewing order of manga follows Japanese right-to-left convention. Too bad Amazon has not seen fit to finish the feature, fix a few bugs, and remove it from its 'experimental' ghetto.

    I'll have to confirm the 'no-delete' of picture folders later - my USB cable is 300 miles away at the moment.

    I haven't tried e-nki yet but as with other Windows tools my problem has been that my laptop is a mac and I lack sufficient motivation to fire up Fusion just to try them out. But I recently acquired a powerful Windows laptop which will gradually claim more mindshare for photo editing and the like once I have time to set it up.

    In terms of usability of the picture viewer, it is worth familiarizing yourself with all the Menu/Aa options and the keyboard shortcuts, even though the options you select don't always 'stick' from one viewing session to the next. For a run-down see the blog article I wrote awhile back:

    or the more compact description on Dianne Gorman's 'kindle 3 keyboard shortcuts' page:

  7. dorachild,
    One person reported, on reddit.com that Cox thought it was a 'phishing' site but others of us haven't had a problem and I have three webbing protectors that don't let me onto sites that are suspected of malicious activity. With all 3, I get no warnings.

    The one person having a problem getting to the webpage said s/he "Just went to the site by proxy" and that was fine. Your browser tools allow you to choose but it's normally better to leave that option as-is. Maybe try another browser?

    Re best image results, the author says:

    "As for making good ones, look for pictures that don't have gradients, that is there is no smooth transition of color like in a sunset.
    Lots of details or hard cut offs look best. And you really can't tell until it's on the screen. As for the ghosting I've never had that problem, what gen are you using, I have a 3rd gen kindle."

    In my experience, you have to add contrast to the image before the Kindle shows it particularly well... but it's not necessary.

    Good luck with accessing the site. I know several hundred have gone onto that site from this blog but I've had this one report of inability to access it.

  8. Thanks for more info on the zip file readability.

    Re the picture viewer, I have no problem using it, since Kindle 1. It's that the photo display, the quality of the photo as described -- contrast, clarity is something that requires some work if you want it to have some punch.

    Will check your blog for any of your entries. Wasn't sure you were keeping it up.

    And, yes, I've mentioned D Gorman's fine shortcuts page here, and she's posted here and I have a bookmark to it. Again, i have no problem with the picture viewer navigation or looking at it.

    As a hobbyist in photography, what interests me is what the image looks like on the Kindle and that is another world, on e-ink with only 16 basic shade levels as opposed to millions, and the way any e-Ink machine interprets color.

    I think it's best to optimize the b/w first and then have the size converted so quickly as can be done, something I do everyday but I don't want to take much time with it.

  9. Thanks, Tom Semple for the suggestion about using PDFs.

    Andrys, I'm surprised no one has mentioned the importance of gamma correction.

    If you correct gamma before you increase contrast, you loose fewer subtle distinctions in the less shaded areas of an image on the Kindle.

    My conversion recipe:
    1) The image must first look good on my computer monitor.
    2) Convert to gray scale.
    3) Apply gamma correction. (1.8 for Kindle 3)
    4) Apply contrast enhancement. (Paint Shop Pro's Clarify @ 15.0)
    5) Resize to fit in a 600 x 800 pixel screen.

    The kindle screen is a 4bit gray scale, NON-GAMMA-CORRECTED, low-contrast device.

    The low-contrast part is easy to understand - The blackest black isn't very black. And the whitest white isn't very white.

    But what about NON-GAMMA-CORRECTED?
    Simply put, gamma is a measure of how evenly the shades of gray are distributed between "black" and "white".
    If there are 16 shades of gray 0-15, do shades 7 and 8 look:
    A) Too light to be at the middle of the scale?
    B) Just right? No gamma adjustment is needed.
    C) Too dark to be at the middle of the scale?

    If you load a 256 shades of gray palette image on the kindle -
    you can see the middle part of the scale is far too dark on the Kindle. A gamma correction somewhere in the range of 1.8 - 2.0 seems to be about right for the Kindle 3 - making the shades at the middle of the scale look about right.

    I'd also like to note that if your software includes more than one choice for adjusting contrast, the item simply labeled Contrast or Brightness/Contrast is probably something of a blunt instrument. Your software's other contrast adjustment items are likely capable of better results. Make your judgments as to which is best based on pictures that include those difficult to display smooth gradients - sunsets; skin tones in close-up portrait shot. If your software happens to be Paint Shop Pro, the Clarify tool with a setting of 15.0 seems to be a super contrast enhancement step. The result on the computer screen is every skin blemish stands in sharp contrast. But when the image is moved to the kindle, you get smooth skin tones with little sign of banded gradients.

  10. MrBookNerd,
    I'm not surprised re no mention of gamma correction.

    The screen converter utilities are just a quick, automated way to put any sized, colored pic onto your Kindle. They don't promise highest quality, although it looks as if E-nki might put some focus on that.

    The Kindle is targeted at people who don't depend on or use computers heavily. Amazon's claim to fame with the Kindle has been that it doesn't require a computer the way other e-readers have.

    Getting into all the adjustments you (and I) like to make is entirely different territory but is good added info for an in-depth future column on optimizing the quality of your image on the Kindle, rather than stopping at automating resizing and grayscale.

    What's good about the Comments section is we can get a note like yours that will be of interest to those who do want more info on making sure you have higher-quality on the image placed on the Kindle. So, thanks for taking the time to write that out.

    It's good advice you gave. As for me, I don't use simple contrast adjustment, which is purely contrast and loses detail. I use Levels adjustment and curves.

    But it's something that wouldn't fit in this particular article about automated screen utilities for those who don't know about the 'pictures' folder (meaning Amazon intentionally created a feature like that) or how to get the right-sized image on it. Grayscale pics are smaller sized as well.

    For me, the clarify tool (in any software) will be used at varied settings based on the size of the image and the degree of sharpness in the shot. But your final point is very good insofar as the difference between the computer and Kindle screen with regard to appearance of the final image. Important if you care about the quality of the image seen on the Kindle.

  11. Hello again, Andrys.

    Here is a link to a picasa web -
    with before and after shots of a wall paper image processed by E-nki, KindleImageConverter.co.cc and me.

    (Links to the full sized images will be found in a separate post.)

    E-nki's output on a computer monitor doesn't look anything special. But, when the image is put on a Kindle, its just dreadful. (Due to a bug in Kindle's rendering of 4bit PNGs.)

    KindleImageConverter.co.cc does a better job with the grey scale - if somewhat lacking in contrast - but it just stretches the image to fit 600 x 800, so results with a landscape format are distorted.

    I understand where you're coming from when you say, "For me, the clarify tool (in any software) will be used at varied settings based on the size of the image and the degree of sharpness in the shot." But aren't you thinking in terms of tweaking the image to look good as possible on the particular monitor in front of you - your reference system? If the image already renders perfectly on your reference system, then doesn't making the same image render as well as possible on the Kindle becomes not a matter of tweaking but of mere TRANSLATION? Pretty much formulaic math with fixed terms and constants? I think the pictures in the album speak for themselves.

  12. MrBookNerd,
    Thanks for all the examples. No time to look yet and probably will on Monday.

    You can make html links. Just use the "a href..." type link, don't use target=_blank and then people can click to get to them. To do it with copy paste is time consuming, but so was typing these for us as you did. Still, more people will click on links than will do copy paste. Thanks again.

  13. Spent at least 30 minutes last night trying to make click-able links. No idea why I never tried straight html! Sometimes I'm just dense.

    Here's the web album

    Comparison results for roll-your-own vs. the two utilities. These are all marked for easy comparison when viewed on a kindle.

    Denali - full original

    Denali - mangled by E-nki
    portrait version

    Denali - stretched by KindleImageConverter.co.cc
    portrait version

    Denali - My simple recipe
    portrait version

    Denali - Recipe + error diffusion
    portrait version

  14. @MrBookNerd,
    thanks for your comments, you are right about 4bit PNG error with Kindle viewer, my mistake was to check the pictures only with doukan firmware, that manages images without problems.
    next version (that will out ASAP) will switch to 8bit PNG.
    About grayscale conversion, gamma and constrast enhancement I will go forward to follow your suggestions.
    If you have other suggestions or comments, you can contact me directly with twitter, facebook or www.e-nki.com

  15. Finally reunited USB cable and Kindle & confirmed:
    - image .zip file item can be deleted from Home screen, and .zip file is deleted
    - image folder item can be removed temporarily from Home screen, but the folder and files remain on the Kindle (ALT, Z restores the item).
    - also, .zip file showed up right away, I had to Alt,Z before the picture folder would show up
    - '.manga..' files show up after viewing pictures, regardless of .zip v folder, and have to be removed via USB.
    - calibre will manage .zip/.cbz files (copy and remove them from Kindle) but not image folders (though again, ignores the '.manga..' files).

    So for my 2 cents, .zip is a better way to go because of the better (though not perfect) file management.

  16. Tom and MrBookNerd,
    Thanks to both of you for the great work, and certainly time-consuming too, that you've done on the various aspects of this.

    Tom and Kindlworld readers,
    I hope people click on Tom's profile to see his two Kindle blogs, both with a lot of detailed information after thorough examination.

    "Kindle Cookies" and "Reads, Rants and Ruminations"

  17. Thanks for the appreciation, Andrys.

    E-nki, the combination of gamma correction followed by clarify/contrast enhancement is something of a kludge. Those are the available tools in standard photo editing software, but its a little like using a screwdriver to hammer a nail. You should see a message from me at www.e-nki.com shortly. I'll try to point you toward a hammer.

  18. There are several images to PDF converters that can be found all across the internet but this JPG to PDF converter outruns all of them in terms of great performance and smooth operation.


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