Apathy Sketchpad

I’ve just added a new download. It’s a screensaver, which displays an image of the Mandelbrot Set, before slowly zooming in on whatever part of the fractal it thinks is probably interesting.

• Code Factory Entry Here
• Direct Download Link Here (7.1kB, requires .NET Framework, which you may already have)

Technical notes:

• The settings screen assumes you understand what the Mandelbrot Set is. If you don’t, the point is that for each point on the screen, the colour represents the number of iterations required before the value exceeds a certain cutoff. You don’t need to know what that means, but the cutoff is one of the options. Since some points (those within the Mandelbrot Set) will never get there, so the maximum number of iterations option lets you choose when it should give up. A higher cutoff will produce smoother colours but take longer to process. A higher number of iterations will produce more detail but again take longer to process.
• The colour step controls how fast the colour changes. A low number will give less contrast but a less psychedelic image.
• The minimum spread to zoom, which must be between 0 and 1, controls how interesting something has to be before it will be zoomed in on. Some parts of the image take longer to process than others, so the maximum difficulty to zoom, which again must be between 0 and 1, controls how long a part of the image could take before it will be ignored. If no area of the screen matching these rules can be found, then it will revert to the entire Mandelbrot Set image and start zooming again.
• After a great many zooms, you start to hit the limits of double-precision floating point numbers, so changing the maximum zooms option puts a hard limit on how many times it zooms before going back to the start. I find the 40th zoom is where it starts going wrong, though to be fair by that point you’re looking at an area that would have been 1% the size of a hydrogen atom at the original zoom level.
• There’s no frame rate limiter in this. If you have a ludicrously fast PC at low resolution, it may run too fast. You could try increasing the first two numbers to silly levels. That ought to slow it right down.
• I have no idea what happens to this screensaver on multiple monitors.

I just uploaded my script for AutoHotKey. It has a clipboard saver, paste-as-plain-text button, Firefox [b] and [i] support (and the same for LaTeX) — you can edit this to whatever browser/TeX editor you prefer), generic support for advanced tabbing which I mostly added for Matlab, launch the highlighted URL (because Opera does it and it annoys me that Firefox doesn’t), and a couple of other things. You’d be better off editing it to suit your needs than using it as-is, but I find it very useful and thought you might too. Everyone should have AutoHotKey, anyway.

Code Factory page: http://www.apathysketchpad.com/codefactory/code.php?id=autohotkey

Direct download link: http://www.apathysketchpad.com/codefactory/file.php?id=autohotkey.ahk

 

 

 

 

I’ve just uploaded a zip file containing five applications I’ve written which you cannot live without. I say this confidently because there are 18 applications in there and I use at least two of them most days at work. Here they are, divided into broad categories. The first category is probably the most useful for non-geeks, the second is indispensable for geeks, and the third is mostly no good to anyone.

The “The Screen Is An Art Package” Applications

These are designed to go in a quicklaunch bar, or in an Aquadock, or something. They all allow you to run simple image manipulation on the entire screen. Some are useful only for people who do a lot of work with images (and don’t want to fire up The GIMP every time they get an email), others are just really, really useful. They are:

• Brightness And Contrast* — make faint images visible without having to copy-paste into an art package.
• Channel Splitter* — toggle display of red, green, blue, hue, saturation, and value of the screen.
• Colour Picker* — find out the RGB code of any pixel. Also shows HTML colour codes which you can copy to the clipboard.
• Copy* — drag a box on the screen and it will copy that area to the clipboard.
• Filters* — apply blur, sharpen, edge detection or any custom filter to the entire screen
• Freeze — prevent an area of screen from updating. You can also use the programme to quickly grab an area of screen, and move it around. It is very useful for comparing graphs, keeping headers in scrolling tables, and making quick notes from a document you’re reading.
• Histogram* — see a histogram of the area of screen you select.
• Morphology* — erode and dilate the screen. Useful really only for imaging types.
• Paintbrush — this allows you to draw on the screen, and then continue to work with the painted lines still visible. This is useful for all kinds of different things, as well as being basically awesome.
• Save* — drag an area of screen, and save it to a file. Nothing you can’t ordinarily do, but it’s so much faster…
• Thresholder** — threshold the screen image.

Regular Expressions Applications

Regular Expressions is a massively useful standard for doing very advanced find-and-replace operations. I’ve built two little programmes around it:

• RegExp — a command line utility that takes standard inputs, applies a regular expressions search to them, then gives the results as standard outputs. It can be used by anyone who understands the Windows console properly to run regexp find-and-replace on any text file or to create a batch file based on a directory structure. To be honest it should have been built into Windows to begin with. Put it in a folder on your PATH environment variable, or else add its folder to PATH (using contol panel > system > advanced > environment variables).
• RegExp File Renamer* — takes a regular expression pattern and a folder of files, and applies the find-and-replace rule to all filenames therein. It’s ridiculously useful. It has a preview feature so you can test the expression before applying it to your precious data, and it can copy, delete, move and rename on demand.

Everything Else

• AnyOverlay — drag a picture onto this window (or load one with the right-click menu) and you can keep it always-on-top, resized, semitransparent, and/or masked to a colour. Useful for aligning things and comparing images. Also pretty handy just for previewing images.
• Coverer And Measurer — tiny application which can be always-on-top (to hide things from people) and displays its dimensions, so you can use it to measure screen distances.
• Folder Viewer* –not the easiest to use application, but it’s designed to help you flick through a lot of folders each with the same images in. I can’t imagine this will be as useful to you as it is to me.
• Text File Combiner — it allows you to combine text files in unusual ways, sticking the new file to the top, bottom, left or right of the old. It’s not great but I’ve used it before and it helped.
• Video Calibration Tool* — calibrate webcams, USB cameras, TV cards, and the like. It shows you the live feed and the histogram, so you can make sure you’re getting the most from it. Probably only of interest to people who need such cameras for something more important than Skype.

You can download it here. All the applications in it require .NET, because they wouldn’t exist otherwise.

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*This was already available from this website but I put it in here anyway because I just don’t care — these mostly belong together, and storing extra data on this server is dirt cheap anyway, and I honestly can’t recall if these programmes have been updated since I last uploaded them. If your RegExp File Renamer is case sensitive then they have; the new one isn’t.**These are available as one combined app, before I split them because it wasn’t practical to add everything else to it.

A bit ago, Randall changed the design of xkcd.com and in doing so very inconsiderately broke my xkcd Wallpaper Randomiser. Well, now I’ve updated it, so if you used to use it then you can download the new version and use it once more.

As before, the source code is available, so you can see just how little has changed and just how easily you could have done this yourselves, you lazy bottoms.

I’ve heard there’s a thing called “Web 2.0″ and apparently it involves a lot of clever design work. I don’t know or care what exactly it is about “Web 2.0″ that makes it better than, or even different to, the old thing (which presumably was “Web 1.x”), but either way it’s time I made my own WordPress skin for this site. So here is my design, which I’m rather pleased with: Read the rest of this entry »

This page will teach you how to write a not-necessarily-very-good programme to beat some common captchas, but it will not provide any useful code to do so for you. It should give you an idea how to go about defeating captchas not listed here. But mostly, I hope it will be instructive for anyone who wants to write a less easily defeated captcha in the future, since apparently you’re all hopeless at it at the moment.

As everyone in the world knows by now, most websites and forums use “captchas” to try and stop computer programmes from posting fake comments containing adverts. “Captcha” stands for “Completely Automated Public Turing test to tell Computers and Humans Apart”. And as everyone in the world ought to have realised by now, they don’t work.

There exist a number of ways around them, the most cunning and most effective, although the most difficult to set up, is to build a pornographic website and get real humans to solve the captchas for you in exchange for naked pictures.

But mostly, they’re easy to get around because they’re shit. This, for example, is the default captcha that comes with the now obsolete phpbb2:

That is very easy to solve. (It should perhaps be pointed out at this stage that my job is in large part to extract shy information from images.) As with all the algorithms I’ll show you, this is the first and simplest one I could come up with, and it’s only the start. In all cases I will extract a binary mask of the letters for transferal to a more general OCR system. Also in all cases, I will use Matlab 6 to perform the analysis. Read the rest of this entry »

Today I uploaded some little gadgets I did a bit ago. They’re handy for some people, not so much for others. If you use a lot of images, they’ll probably be useful to you. They need .NET, mind.

I have, of late, been writing my own forum script, which I intend to use on this site and am considering releasing as open-source because I’m not selfish. So as such, the new forum is now officially open at http://forum.apathysketchpad.com.

It features no admin panel, because they’re too easily hacked and in any case I prefer to hack the database in PHPMyAdmin and hack the behaviour in the PHP files, so I’ve made all the code as readable and abstracted as I could to make this easier. It also features fully native support for all kinds of cunning levels of sticky threads, closed threads and Anarchy Boards that just aren’t possible in most forum scripts. It’s based heavily on the CMS I made for RealVG, and it takes a very different approach to most forum scripts, not least because I don’t see the point in spending a lot of time producing something that already exists. It’s very well suited to small site run by people who know their way around PHP (such as this one), but less well suited to large sites with many staff members (as they’d all need FTP and PHPMyAdmin access to administer it) or sites run by people who don’t know their way around a web server (because they’ll not be able to set it up, not least because there’s no installer at the moment). Since it has no admin panel, no session IDs (cookies are required), and checks your password on every page, it is, as far as I know, totally secure. I’ve little doubt there’ll be a hole in there somewhere, but keeping things simple and well abstracted is always the best way to keep them secure, and I think I’ve done that fairly well.

Other features I intend to add are email thread subscriptions, Facebook style user “walls” and the ability to email users who say they don’t mind (but not private messages because I don’t see the point), and some kind of file attachment system. And a “forgot my password” link, because they’re always useful. Also there are a lot of extra fields like “edited by” links that will need adding to the skin.

So feel free to register and post there, but do bear in mind that me and Testing Jeff will just spam mercilessly until the beta is over. And feel free also to request features and report bugs — that’s what beta is for. Such reports should be in my email inbox, comments on this post, or in the special beta test subforum.

The old forum will stay where it is indefinitely, though it won’t be reopened (for the forseeable future). I’ll update the various links later, and possibly put a notice on the old forum explaining where the new one is.

There. I’ve said it.

Reason being, my phpBB forum keeps getting hacked, by morons no less, because it features the world most insecure admin panel. I don’t know if you’ve ever clicked the “administration panel” link at the bottom of a phpBB forum. It’s a tiny link at the bottom of pages which is only displayed to administrators and anyone else who wants to see it badly enough. When you click it, a large button appears saying “please don’t click here if you are a hacker”, and clicking it automatically takes you to the admin page. The admin page has three options: ban users, change the kind of captcha you use, and change the index page to say “Joo hav been hacked by Captain Awesome’s CyberDweeb Klan” and play shitty music. I understand phpBB employ people specially to compose this music.

Whatever the reasons behind this insane design philosophy, the result is that phpBB is a total chunk of crap. So what I’m doing is writing my own forum script. My forum script is better than phpBB. Sure, I’ve not added any way for users to register, so I’m the only person who can post, but that’s one better than phpBB, since I’ve had to take away phpBB’s access to my database, so even I can’t post there without doing it via PhpMyAdmin. Secondly, it is impossible to hack the admin panel on my forum script, because it hasn’t got one. Nor does it have a moderator’s panel that can delete all the threads at once. That’s just asking for trouble in my opinion. And you don’t need these things. At least, I don’t.

phpBB is, I think aimed at people who want a cheap forum for their website and want to have a team of moderators and admins watching over it and doing handy things. Mine isn’t. Mine is aimed squarely at me. It does things my way. If you want to change the look, you change the PHP files. If you want to edit the forum list, you use PhpMyAdmin. If you want to ban a user, PhpMyAdmin. If you want to delete a load of threads at once, PhpMyAdmin.

It’s a much better system. It’s more flexible than phpBB’s mod controls (which are useless at best) and it’s infinitely more secure. Once it’s up and running, my new forum will be at forum.apathysketchpad.com. Well, it’s up there now but it’s nothing but meaningless testing banter at the moment, so there’s little point in looking at it (though I’ve no doubt someone will).

I don’t really understand phpBB. I’ve looked at the source and it’s crazy. The database is split across a hundred things; they take away your RegExp and give you a rubbish asterisk system, which the code then turns back into RegExp. The posts are stored across two tables. The whole thing is just madness in a jar.

So I’m doing it myself. Honestly, it seems like the only way sometimes.