Instead of dumping all those intermediate images in temp files along the way, ImageMagick offers a nice, clean way to build a transient image.
#Linux imagemagick wiki download
(In fact, there is a pseudo-image called "rose:" which is actually a photo of a rose that ships with ImageMagick, a brilliant feature as it means people can write tutorials that manipulate the image without requiring you to download it.) We can generate a gradient image using a gradient pseudo-image. Go on, type this in right now to make a pure red GIF image:Ĭonvert -size 3000x120 xc:red /tmp/red.gifĬanvas is only one example of a pseudo-image there are pseudo-images based on patterns, fractal generation, etc. To create a pure red image, we use a pseudo-image of type Canvas, mysteriously named "xc". But we want to create an image from nowhere, so what ImageMagick lets us do is create an input image from thin air, a "pseudo-image". "convert -transparent white normal.gif transparent.gif". ImageMagick usually works by converting one image to another, e.g.The trick relies on several features of ImageMagick, pseudo-images, image stacks, and appending: If you want, jump straight to the one-line examples below. You can generate (and therefore easily tweak) logos, curved surfaces, etc, but what I’ll talk about here is gradient images. Fortunately, there’s this set of examples.
#Linux imagemagick wiki how to
Unfortunately, it’s not too well documented - the official docs are thorough, but completely lack examples (a common problem with open-source projects is documents oriented around the features rather than the typical tasks, and often in the absence of any useful examples that in this case would show how to construct a command-line). Until today, I’d only ever used it for transformations, but now I’m using it for image generation too. ImageMagick, which usually is executed with the “convert” command, is probably installed on your Unix/OSX machine already and your Linux web host as well (many Captcha utilities use ImageMagick to create and warp the image). Using ImageMagick, it’s possible to do tons of things on the command line. Solution: Generate images on the command line. Or, you might be able to just make the change in your editor, but even that will take a lot longer than editing the CSS file, anywhere between 10 and 100 times as long (usually 1-5 minutes versus 1-5 seconds). However, contemporary gimmicksconstructs like curved surfaces and gradients aren’t yet supported, which means simple tweaks - like changing a colour - usually require a round-trip between a graphical editor (Photoshop, Gimp, etc) and your CSS file. Problem: The great thing about standards-based web development is how easily you can tweak the look by modifying CSS properties. Command-Line, CSS, Design, Gradient, HTML, ImageMagick, Tutorial, Web2.0