Archive for the ‘Open Source’ Category
Photocrumbs is another spare-time project of mine. Every now and then, I need to quickly throw a handful of photos on the web without going through the rigmaroles of using a full-blown photo sharing solution. So I cobbled together a super simple single-file PHP app for instant photo publishing. Photocrumbs is essentially a single PHP script (plus a favicon.ico file) which can be deployed in a matter of minutes on any web server with PHP and the GD library. Drop the script into a directory writable by the server, and you are good to go (see the project’s page for more detailed installation instructions). To publish photos, simply copy them into the photos directory.
Photocrumbs’ claim to fame is the expiration functionality. When enabled, it automatically deletes photos that are older than a specified number of days. This way, you don’t have to remember to manually remove temporarily published photos. This feature is disabled by default, but you can easily activate it by editing the appropriate settings.
Other Photocrumbs niceties include the ability to add descriptions to each photo (either by entering text into the UserComment EXIF field or by creating an accompanying .php file), and support for basic EXIF info. For each photo, Photocrumbs displays key info like aperture, shutter speed, ISO, and timestamp.
Although I use Pygmynote on a daily basis, I haven’t tweaked it for a while. Basically, the script does what it’s supposed to, and I didn’t feel an urgent need to improve it.
Over the weekend, though, I finally got around to implementing a couple of small features as well as cleaning and tweaking the code. Continue to read.
Serious Android photographers need a serious camera app that offers advanced functionality and is not overloaded with useless features. They need something like Focal. This open source app is still at an early stage of development, but it already shows a lot of promise, and it has the potential to become a viable alternative for Android photography enthusiasts.
Focal features a streamlined interface which makes it easy to take photos and operate the app. To change the focus point, tap on the desired area on the screen, then tap the Shutter button to take a photo. To switch between the supported shooting mode, tap and hold the Shutter button, then swipe up to activate the semi-circle with the available shooting modes. Slide the finger to the desired mode to enable it. Besides Panorama and Video, Focal supports the so-called PicSphere mode which is an open source implementation of Google’s popular Photo Sphere feature that allows you to snap multiple photos in every direction and then automatically stitch them into a single panorama image.
Focal allows you to quickly preview taken photos by swiping down from the top of the screen. This displays a thumbnail gallery which you can browse by swiping forward and backward. The gallery features two buttons that can be used to open the currently viewed photo in an external photo viewer or photo editing app.
To access Focal’s options, swipe from left to right starting at the edge of the screen to evoke the main toolbar. Each button on the toolbar opens a palette containing the available options. Most buttons here — such as White Balance, Exposure Compensation, ISO, and Flash — should be familiar to most photographers. Using the appropriate buttons, you can select between different scene modes and effects. The HDR button lets you enable the HDR feature which automatically takes three bracketed photos. Focal supports several burst modes, and you can use the Burst button to enable the burst mode you want. Each palette can be pinned to the screen, making it easier to quickly access often-used options. Better still, all settings adjustments are persistent, so you don’t have to enable and configure the options every time you start the app.
Since Focal is still labeled as beta, some features are still missing. For example, the app doesn’t support different focus modes (manual, macro, etc.) and there is no way to change the default storage location. Moreover, some features can behave erratically. The PicSphere, in particular, can be rather temperamental at times.
Recently, I bought an EPSON Perfection V500 scanner, and I spent last weekend scanning piles of negatives. One thing about scanning negatives is that it involves a lot of waiting: you click the Scan button and then wait till the contraption does its scanning thing.
Meanwhile, you need to find a diversion to keep you entertained. Having a good game app for Android would definitely help. And after rummaging through the F-Droid repository, I found a perfect candidate for the job. FreeShisen is based on the Shisen-Sho Japanese game. The game has a lot in common with the popular tile-based game of Mahjong, but it has more elaborate tiles and rules.
Despite that, you can master the game’s basics in a matter of minutes. Depending on the level of difficulty and your skills, a single game usually takes between 5-10 minutes — perfect for passing time between scans. The app is open source and available through F-Droid and Google Play Store.
There are plenty of reasons to choose Debian, but having the most recent versions of your favorite applications is not one of them. Software updates trickle down to the stable version of Debian very slowly, which means that packages in the distro’s repositories are likely to be a few versions behind the current releases. digiKam is no exception: the Debian stable repositories contain a version of digiKam which can be considered outdated. However, if you don’t mind the risk of making the Debian system unstable, or even breaking it altogether, you can opt to upgrade the distro to unstable and then install the latest version of digiKam from the experimental repositories. (Note: all commands mentioned below must be executed as root.)
The first step is to upgrade Debian to unstable. To do this, run the nano /etc/apt/sources.list command to open the sources.list file in the nano editor. Disable stable and security repositories as follows:
Add then the unstable repositories:
Press Ctrl+X to save the changes and close the editor, then run the commands below to update repositories and upgrade the distro:
apt-get update && apt-get dist-upgrade
Once you’ve done that, open the sources.list file for editing again and add the experimental repository:
deb http://ftp.debian.org/debian experimental main contrib non-free
Save the changes and run the apt-get update command. You can then install the latest version of digiKam from the experimental repository using the following command:
apt-get -t experimental install digikam
If everything goes smoothly, you should have the most recent release of digiKam installed on your system.
If you are looking for a no-frills depth of field calculator app for Android, you can do much worse than giving the DoF Calculator a try. Released under the GPLv3 license, this app has the virtue of doing one thing well: calculating the depth of field and limit values for any given camera model, lens focal length, and distance to the subject combination.
DoF Calculator is not available in the Google Play Store, but you can either sideload it using the latest APK package from the project’s website, or install the app through the F-Droid market. Unsurprisingly, DoF Calculator is very straightforward in use: pick the desired camera model, focal length, aperture, and the distance to the subject, and tap the Calculate button. The app then returns three values: near and far limits along with the total depth of field.
A new version of the digiKam Recipes ebook is available for download. All screenshots and material have been updated to reflect changes in the most recent version of digiKam. The new release of the ebook also features the new Apply EXIF Metadata to Multiple Photos recipe and a refreshed cover.
Readers who already purchased the book will receive the new version free of charge. If you haven’t received your copy, please send your order confirmation as proof of purchase to firstname.lastname@example.org, and I’ll email you the latest version of the book.
If you happen to use digiKam for managing photos scanned from negatives, you’ll appreciate the application’s capabilities to add and edit EXIF metadata. Using digiKam’s dedicated interface for managing metadata, you can add key EXIF values, such as maker, device model, aperture, shutter speed, ISO, focal length, etc., to the scanned photos (provided you have these data handy).
However, digiKam doesn’t allow you to apply the same EXIF data to multiple photos in a single operation. Adding the same maker, device, ISO, and focal length to a set of photos one-by-one can be a bit of a nuisance, but you can use a simple trick to work around this limitation. Start with adding EXIF values to a single photo. Select then the rest of the photos, choose Image → Metadata → Import EXIF, pick the processed photo, and press OK. This will apply EXIF data from the processed photo to the selected images.
Bugs are inevitable in complex software, and digiKam is no exception. So what should you do when you’ve discovered a bug in your favorite photo management application? As a non-programmer, the best thing you can do is to file the bug with the KDE bug tracking system (digiKam is managed as part of the KDE project). Submitting bugs can be considered a tedious task, but this greatly helps the developers to improve digiKam, and the KDE bug tracking system makes it relatively easy to file bugs and issues.
First of all, you have to create an account with the bug tracking system. To do this, point your browser to https://bugs.kde.org/, press the New Account button, and create a new account. Once you’ve done that, log in to the system using the specified credentials. Before you submit the bug, it’s important to make sure that it hasn’t already been filed in the system. Click the Search link, select digikam from the Product drop-down list, enter the keywords that best describe the bug in the Words field, and press Search. Check the list of the matching results for entries similar to your bug.
If the bug doesn’t appear in the search results, you can submit it to the system. Click the New link at the top and select digiKam from the list of KDE projects. Since you’ve already checked for similar bugs, you can skip Step 1 and go directly to Step 2. The fields in the bug filing form contain brief descriptions and examples, which make it easier to provide the relevant data. It’s important to give as much information as possible, as this helps developers to reproduce, identify, and ultimately fix the bug. Double-check the entered information, and hit the Submit Bug Report button. You can view all your filed bugs using the My Bugs link in the Saved Searches section.
Using tools available in digiKam, you can simulate a number of effects, including bleach bypass. This effect produces a desaturated high-contrast image. Creating the bleach bypass effect in digiKam is done in two simple steps. Open a photo for editing and choose Color → Hue/Saturation/Lightness. Specify the desired saturation value somewhere between -35 and -59, then press OK to desaturate the photo.
Choose then Color → Curves Adjust, select Luminosity from the Channel drop-down list, and adjust the curve so it’s shaped as S. Feel free to experiment with the steepness of the curve to achieve the best result. As a starting point, you can download a ready-made S curve and import it into digiKam using the Load button.