by So, we want to get a gif that's an odd size cut down to something signature friendly, or remove some unsightly part of it. Easily done with ImageMagick, so let's go through the steps:
- 1. Find your image. For this example we will use the following (by Mattthesamurai), renamed as "GifExample.gif".
2. Save it somewhere easy to navigate to, like the Desktop.
3. Open up the command line by going to "start..." --> "run..." and typing in "cmd", then press enter. On Vista/7 you can just type "cmd" in the search bar to start it. For help on other platforms, consult the IM documentation. Navigate to the location you saved the image to. For the desktop, just type "cd desktop" to get to that directory.
4. Now, you need to work out how much you want to remove. Think of this like a window that the gif will be seen through; anything outside the window will be lost. So, either guess or work out how large the dimensions of the window should be, and the displacement (offset of location) for the window. Don't worry if this is the wrong size (in terms of pixels) for what you finally want as long as it's the content you want to keep in the right aspect- we can resize later.
In this example I want to grab the red area demonstrated below. This corresponds to 455 pixels in width and 182 in height. The displacement of this is +0 pixels in the X direction (from left to right) and +259 in the Y direction (up and down). Note that the displacement is specified from the top left of the image and right and down are always positive values.
5. Right, so we have the things we need, let's remove the parts we don't want:
Generic command!
convert <input>.gif -crop <X>x<Y>+<X Displacement>+<Y Displacement> -trim +repage <output>.gif
Where <input> is the input image, <X> is the width of the window, <Y> is the height of the window, <X Displacement> is the offset in width, <Y Displacement> is the offset in height and <Output> is some output name.
For our example it looks like:
convert gifexample.gif -crop 455x182+0+259 -trim +repage gifexample2.gif
As we are cropping to a window of 455 pixels by 182, with an offset of +0 pixels in X and +259 in the Y direction.
So we get:
Great! It's trimmed everything like we wanted and it's retained the image as a gif at the same framerate as the original image. If you have it the size you want already, you're done. If you want to resize, you can do so with the resizing gifs tutorial.
I hope this helps you with your signature image hunting!
