MacOS provides a few different ways to do screen captures. My personal favorite is Grab, which is found in the Applications/Utilities folder. It lets me capture a selection, a window, or the whole screen without having to remember any magic key combinations. I keep it in the Dock for quick access.
Grab has one deficiency, though. It can save screenshots only as TIFF files. If Apple had to pick just one format, that’s hardly the most useful one. But there’s an easy workaround.
After you’ve got your screen shot, press Command-C or choose “Copy” from the Edit menu. Open the Preview application. Press Command-N or select “New from clipboard” from the File menu. You now have the screenshot in Preview.
In Preview, press Command-S or choose “Save…” from the File menu. You’ll get a dialog to save the file, with a choice of formats: JPEG, JPEG2000, OpenEXR, PDF, PNG, or TIFF. Pick whichever one you like. If you’re going to put the image into a Web page, PNG is usually the best choice. Preview will remember your choice for next time. Then save the file.
If you prefer, you can do the equivalent in Photoshop, Gimp, or any other image-processing application, but Preview has the advantage of launching quickly and keeping the process simple.
That’s it. You can now use Grab to save screenshots to a Web-friendly format.
Lately I’ve ghostwritten several pieces on Internet security and how to protect yourself against malicious files. One point comes up over and over: Don’t hide file extensions! If you get a file called Evilware.pdf.exe, then Microsoft thinks you should see it as Evilware.pdf. The default setting on Windows conceals file extensions from you; you have to change a setting to view files by their actual names.
What’s this supposed to accomplish, besides making you think executable files are just documents? I keep seeing vague statements that this somehow “simplifies” things for users. If they see a file called “Document.pdf,” Microsoft’s marketing department thinks people will say, “What’s that .pdf at the end of the name? This is too bewildering and technical for me! I give up on this computer!”
They also seem to think that when people run a .exe file, not knowing it is one because the extension is hidden, and it turns out to be ransomware that encrypts all the files on the computer, that’s a reasonable price to pay for making file names look simpler. It’s always marketing departments that are to blame for this kind of stupidity; I’m sure the engineers know better.
Apple is introducing a new file system to replace the twentieth-century HFS+. The new one is called APFS, which simply stands for “Apple File System.” When Apple released HFS+, disk sizes were measured in megabytes, not terabytes.
New features include 64-bit inode numbers, nanosecond timestamp granularity, and native support for encryption. Ars Technica offers a discussion of the system, which is still in an experimental state.
iTunes is horrible and keeps getting worse. The current version has come down with dyslexia; it can’t even play my files in order. On top of that, it supports a poor range of file formats, knowing nothing about popular open formats like FLAC and Ogg Vorbis. QuickTime Player has a saner user interface but the same format limitations. If you want to play music in those formats, you need to look for other software. I’ve just grabbed Vox for OS X, and it handles those files nicely.
It’s not an iTunes replacement, even if all you want to do is play music that’s stored on your computer. You can import your iTunes library, but you can’t view the contents of your playlists (which it calls “collections”) or select items from them. What it does let you do, though, is play FLAC, AAC, ALAC (Apple Lossless), Ogg, MP3, and APE files.
My current main project is creating a course to offer on Udemy on file format identification tools. As currently planned, I’ll cover file (the command line tool), DROID, ExifTool, JHOVE, and Apache Tika. Covering more than five tools in one course would make it too big, though I might consider changing the list. If I can keep my schedule, I’ll have it out in December for early feedback, giving me a chance to clean it up before MIT’s Independent Activity Period in January.
Right now I’m occupied with the mechanics. The course insists on 1280 x 720 pixel video, so I need a new camera; a friend is selling me a Canon Elph 520 HS cheap. Screen capture software is proving interesting; I’ve looked at three different Macintosh applications so far.
On Wednesday, September 4, 2013, I talked with a small gathering of the Mac Tech Group at MIT on “Rescuing Macintosh Files.” There was a good discussion, with several people contributing valuable points.
The computer presentation which I used is available as a Powerpoint or OpenOffice document. The PowerPoint one had some problems at MIT with displaying all the images, so if you have a choice the PowerPoint one may work better.
I’ve packaged up JHOVEView 1.9 as an OS X application. It’s the same as the regular JHOVEView, except that it’s a little prettier. You can download it on SourceForge as JHOVEView_OSX.zip.