tech.am

Resolution is a term that expresses how well the graphic presentation shows the spatial details in a picture. It is a measure of the fineness of the picture elements. Digital images consist of a large number of picture elements (pixels) in rows and columns, each with a defined color. A pixel is one of many cells that form a picture. An image may extend X pixels from left to right and Y pixels from top to bottom, and contain X times Y pixels. A user has some latitude in how many pixels are used to display a certain picture. For example, the monitor has a few settings for selecting the full screen presentation. The most commonly used resolution setting is 800 X 600 pixels. If every pixel is actually seen (including the corners of the image), there will be 480,000 of them.
Modern digital cameras have frame sizes of 2 megapixels or 4 megapixels, so the need to re-size and crop these images becomes important. If a full-frame image is received as an attachment, the recipient may see only the upper-left corner of the image unless they do some scrolling. Then they may like to make the picture small enough so that it is more readily viewable without scrolling.
Re-sizing and cropping are topics discussed later.
Most viewing software applications (and printers) display the typical image formats BMP, JPG, and GIF at 96 pixels per lineal inch. If a user wishes to stretch a given image file for presentation or for printing, they will get no better resolution by zooming in to make the image bigger. If an image file is modified by stretching or shrinking the overall dimensions, the software must find a means for making the picture information accommodate a newly formed matrix of pixel sizes or pixel count. If the pixel count changes, the picture must retain its basic character, yet the color assignments of the new set of pixels is not the same as the original picture. The software must have algorithms that account for these requirements. The ability of software to accommodate these zoom requirements varies from one software package to another. A test of the quality of image-modifying software is to note if there is significant degradation of an image if it undergoes a series of changes. One of the more noticeable degradations due to zooming will appear in the quality of the text. A particular font type and size will have specific pixel cells blackened.
If you depart from the resolution in which the text was acquired, some software will have a tough time keeping the boundaries between black and white organized so the stroke width and precise shape of the text characters are maintained or simulated. A zoom-type feature may be used in the MS Paint application by commanding Image|Stretch/Skew. When the Stretch and Skew dialog box appears, you will note that there are small highlighted windows opposite the words Horizontal and Vertical in the upper (Stretch) panel which each say 100%. To shrink the picture to half of the original image dimensions, you do so in two steps.
First, click (dropping a cursor) in the Horizontal (small) window, and replace the 100% with 50 %, and click on Okay.
Then do the same for the 100% value in the Vertical (small) window, and click on Okay.
Scanner software generally has choices of scan resolution, as well as black and white vs. color, and a further determination of gray scale or simply black OR white coding when choosing black and white. The latter distinction is important when choosing whether you need two levels (one bit) of gray (either black OR white) or many levels (gray scale), which affords a more accurate rendition of the source material. Most often, you will find that the scanner software offers about five default settings for making these selections, and the means for making custom settings which depart from the default values. A large picture will produce a large image file, and settings that provide more picture details will make that file even bigger. The temporary image format used in scanner software and in image conversion software has no compression (i.e., all picture information is defined within each presented pixel). Thus, the user should note that it takes time for a slow computer to compile all the necessary data to form and to reformat this image if an unusually large, detailed image is being used. In fact, users should be aware that limitations of computer processing speed may not be apparent until you use large media files like a large color photos with high resolution. A user should be judicious in the choice of the scanner settings to make an image file having suitable spatial resolution and color resolution (the fineness of allowed step changes in the color palette) so that the selected resources are appropriate for the end result. Another image format is available that provides for more than 96 dpi resolution. Although the scanner software can accommodate resolutions that exceed 300 dpi, the user may wish to transfer that file to another computer which doesnt have the same scanner software. The format most often used for this purpose is TIF or TIFF. The TIF format provides for resolutions of 300 dpi, or other values which may be set when encoding the file. Also, it will encode either as uncompressed or compressed (JPG and LZW are compression options). The software application needed for creating a TIF file is (Kodak) Imaging, which is automatically installed with modern versions of Windows. Like MS Paint, Imaging will accept images from a clipboard, but you must define the spatial resolution and the color depth unless you are willing to accept the default settings. Imaging can be used for pictures of higher resolution than MS Paint, as it supports spatial resolutions greater than 96 dpi.
A user can copy or export scanned high-resolution images to JPG , GIF, or BMP formats, but the picture dimensions will increase to match the defined 96 dpi for these formats. If images are exported into TIFF format in Imaging with a resolution that matches that of the image exported from the scanner software, the dimensions wont change. The JPG and GIF formats have become standards for use on the internet, as they are able to reduce file sizes while preserving picture details. This is accomplished with the use of sophisticated algorithms that make choices about the picture elements (pixels) whose color definition dont change from the one which precedes it in the defined sequence of forming the pixels into the file.
In this sense, the algorithm votes out the data associated with certain pixels if there is no change from its preceding neighbor. In the viewer software, its algorithm has the ability to reformulate the original image in the absence of the data for those pixels whose color data was voted out. Also, web browsers will present files in JPG and GIF formats, while many web browsers may not present some of the other formats.
JPG file creation depends on a quality selection, often made by the user, in which the user makes a trade-off between the requirements for retaining image quality, and the resultant file size. Thus, a user can make a file with less than 100% quality retention if a smaller file size is desired. A JPG file is most often selected if the picture contains subtle shadings of color, and a small file size is desired. A JPG quality factor of 70% is often acceptable, as it represents a good trade-off between picture quality and file size. A GIF file is often chosen for tables, figures, cartoons, clip art, etc., where few shades of color are present. Choosing the GIF format for this kind of picture often results in a smaller file than a JPG file would provide. GIF is often used for the collection of small image insets which are placed on a web page. If a GIF file of appreciable dimension is shown in the top half of a web home page (so a visitor will see the image form on their screen), the visitor may notice that this image forms in a way which may seem distracting, since the picture elements form in cells much bigger than a single pixel, and these cells become progressively smaller as the fully resolved image takes form. This effect usually is not noted in GIF files of small dimension.

DSL (Digital Subscriber Line) sorgt für einen schnellen Internet-Zugang über ein Telefonnetz. Im Vergleich mit Internetanschlüssen über ISDN oder ein Telefonmodem liegen die Datenübertragungraten um ein Vielfaches höher, wofür bislang nicht genutzte Frequenzen des vorhandenen Telefonnetzes sorgen.

Schnell, schneller, am schnellesten: Seit der Einführung von DSL in Deutschland hat sich die DSL Geschwindigkeit kontinuierlich erhöht. Galt zu Beginn der DSL-Ära ein DSL Anschluss mit 768 Kilobyte in der Sekunde als das Maß aller Dinge, so ist mittlerweile DSL 6000 der Standard-Anschluss und auch DSL 16000 bereits vielerorts verfügbar. Ausschlaggebend für diese Expansion ist die Weiterentwicklung der Breitbandtechnologie ADSL.

Im Zuge dieser Geschwindigkeitserweiterung erhöht sich auch die Zahl der Anwendungen, die im Internet durchgeführt werden können: Internet-TV, aufwendige Online Games und Video-on-Demand machen den Rechner zur Multimedia-Zentrale. Immer mehr User verschaffen sich deshalb eine DSL Flatrate, mit der sie zum monatlichen Festpreis alle laufenden Internetkosten abdecken. Auf Grund der steigenden Nachfrage bieten DSL Provider ihre Flatrate Tarife mittlerweile zu sehr günstigen Preisen an. In der Regel bekommt man eine DSL Flatrate für weniger als zehn Euro.

Auch DSL Telefonie lässt sich über eine monatliche Pauschale abwickeln. Mit einer Telefon Flatrate führt man Tag für Tag kostenlose Gespräche ins deutsche Festnetz – dabei ist sie ebenso preiswert wie eine DSL Flatrate. Volumen- oder Zeittarife, bis vor kurzem noch akzeptabele Tarif-Option, verursachen bei täglicher Internet-Nutzung inzwischen erheblich höhere Kosten als DSL Flatrate Angebote. Deshalb gilt: Am Günstigsten fährt man derzeit mit einer Doppelflatrate.

Ein DSL Zugang besteht aus drei grundlegenden Komponenten: DSL Anschluss, DSL Hardware und DSL Tarife. Einen DSL Anschluss bekam man bis vor einigen Jahren ausschließlich bei der Telekom oder einen ihrer DSL Reseller. Reseller heißt Wiederverkäufer, womit die Unternehmen gemeint sind, die die komplette DSL Technik der T-Com nutzen und einen Internetzugang nur unter dem eigenen Firmennamen vertreiben. DSL Kunden mussten, um die Reseller Angebote nutzen zu können, immer auch einen Telekom-Telefonanschluss haben.

Dies hat sich inzwischen geändert: Immer mehr Provider bieten einen DSL Anschluss inklusive DSL Telefonanschluss an. Der DSL Zugang läuft so völlig unabhängig vom “Rosa Riesen” und insgesamt sind diese Komplettpakete oftmals deutlich günstiger. wer Internetanschluss und Telefonanschluss aus einer Hand bestellt nutzt einen weiteren Vorteil: Man bekommt die monatliche Abrechnung von einem Provider und spart sich sonst anfallenden Papierkram.

 
Ein DSL Anschluss hat immer eine bestimmte DSL Geschwindigkeit. DSL Geschwindigkeit bezeichnet die Leistungsstäke, mit der ein Internetzugang datenübertragungen durchührt. Will man beispielsweise nur Surfen und chatten ist kein DSL Anschluss mit hoher DSL Geschwindigkeit vonnöten, da die Datenrate bei diesen Anwendugen vergleichsweise niedrig ist. Anders sieht es aus, wenn mit dem DSL Zugang Multimedia-Funktionen vorgenommen werden. Um für Online-Games oder eine Übertragung live gestreamter Spielfilme eine geeignete Performance-Qualität zu erreichen bedarf es eines extrem schnellen DSL Zugang.

Bevor man sich einen DSL Anschluss zulegt sollte also auf jeden Fall eine Bestandsaufname dessen gemacht werden, was man von seinem Internetzugang erwartet. Und wenn der bestellte DSL Zugang im Nachhineien doch nicht genügend DSL Geschwindigkeit bietet lässt sich dies in der Regel schnell ausbessern; sofern man nicht bereits die höchste am Standort zu Verfügung stehende DSL Geschwindigkeit nutzt. Denn so ziemlich alle DSL Anbieter ermöglichen ein Speed-Upgrade auch nach Vertragsabschluss.

Open WebMail is a webmail system based on the Neomail version 1.14 from Ernie Miller. OpenWebMail is a full-featured webmail, addressbook, calendar, and webdisk system that is designed to manage very large mail folder files in a quick and memory efficient way.

Started in 2001, it is written in Perl and available for free under an open source BSD license.

Latest Official Releass of OpenWebMail are packaged as tarballs and are available at

I could not resist, having video on an iPod the size of the new Nano was just too tempting…so I got one. As soon as I connected it to iTunes, it prompted me to install the software update that was made available a couple of days ago, after that it synced music & videos, and off I went.

Much to my surprise, this afternoon it started behaving erratically – whenever I pressed the fast forward or rewind buttons, the iPod would keep skipping in the same direction until either the end or the start of the song was reached respectively. One annoying thing is that the skip steps are much bigger than on the previous Nano, and so it makes the process less accurate. Combined with this bug, it’s unusable. The only way to stop it is to pause, and resume playback, and since the steps are so large, it’s a hit-and-miss proposition.

Here is a short video showing the behavior.

It actually indicates GPRS attachment status, the capability (or lack thereof) of sending and receiving data, be it over plain old GPRS, or the faster EDGE. I was going to comment on the original Engadget blog post, but after seeing a few pages of comments already, I doubt they would have noticed it. This is where they get it wrong:

You’ll notice the iTunes WiFi Store icon, and an O2-UK network symbol up top. If you look carefully, you’ll see that the E logo for EDGE is missing: we guess that 30% network coverage on O2 don’t quite stretch inside the Apple Store.

A bit further down, they mention this again:

O2 iPhone on the left, unlocked US iPhone on the right (running on T-Mobile’s UK network). Note that the O2 iPhone doesn’t show the EDGE logo, but the unlocked phone on T-Mobile does. You can probably guess at what we’re getting at here: O2’s EDGE coverage sucks.

In this particular side-by-side photo, T-Mobile’s coverage is marginally lower than O2’s, but they should both be capable of sending GPRS traffic. Another reason they get this wrong is that the waves icon ‘overwrites’ the E symbol while the iPhone is connected to a WiFi network, so you could still have GPRS/EDGE attachment in the background, so-to-speak. In my particular case, the iPhone is happily registered on Vodafone Spain, and is attached to GPRS (no EDGE here at all), showing the E while I’m not in range of WiFi.

The iPhone also does something very clever – when you open an application that requires a data connection, it will start a GPRS attach and session, while it asks you if you want to join any of the nearby WiFi networks (if any). In case you say no, the alternative data connection is already established, cutting down on extra waiting time before you start seeing content on your screen. This may seem stupid to Europeans, by default stuck with hugely expensive pay-as-you-go data (50 Euro cents per 250kB!!), but with the original AT&T voice + data plan, it does not really matter.

And Telefonica, who owns them, just as much. If the rumors are true, they will be surrendering around 40% of revenue (not profit, revenue) from each client using an iPhone, in exchange for an exclusive distribution deal in the UK. What is going to be the likely problem for end users here? Traditionally, when you buy a phone in Europe that is tied to a contract, you have to sign the papers before you can even smell the phone, and thus are bound by the terms. In the US, you can just buy the phone at the store, take it home, and get the contract set up with AT&T through iTunes there while sipping a coffee.

Unlocking your $400 iPhone is now possible, and so you’re no longer bound by an AT&T contract. In Europe, however, you may be able to unlock the phone just the same, but you will have to stay with the contract or pay the cancellation fee. Either way, operators stand to have better deal than AT&T.

Last Saturday, while reading through my feeds, I noticed this post on TechCrunch by Duncan Riley, where he tells the story of an attempt by scammers to get his Skype credentials (and wonders why they’d want to do such a thing), much in the same way we’re accustomed to receive emails from PayPal, eBay, and almost any bank on earth. These emails claim there is a problem with your account, and you should ‘confirm your details’ in order to stop said account from being suspended. This will of course do nothing other than give your credentials to these criminals for unhealthy purposes.

Today, a friend that I had not chatted with in some time comes online, and sends me this:

My first thought has been “Uhm, why would Mike send me something like this?”. He’s not prone to even send smilies, always very short and to the point. I go to ask him about it, but I then notice he is in do-not-disturb mode, so I cannot even warn him about the now-obvious scam! It seems that phishers and other scum are realizing people fall for email traps less and less, and are attacking other more trustworthy systems. In this case, the attacker is sending a screensaver, most likely loaded with a trojan. Beware of -any- communication, even from friends, that is unusual in timing, behavior or content. Also, beware about being asked for your IM details, and use strong passwords.