Slices of image in GraphicMagick - node.js

Question

I have read in the docs, that when you do not specify x, y in the following method, that the image is sliced in to strips:
gm(image).crop(1280, 1)
However! It still only slices as if you write the method as:
gm(image).crop(1280, 1, 0, 0)
http://www.graphicsmagick.org/GraphicsMagick.html#details-crop
Has anyone had this problem, and is there a way to force slices of the given image?

Answer 1

Ok, so if anyone else finds this useful, this was my solution to making a function to iterate through an image and make slices:
/*
SLICE IMAGES
*/
// saved images as an array
var images = fs.readdirSync('captures');
// amount of saved images on disk
var imageCount = images.length;
// assume there are no images currently
var imageCounter = 0;
// create a random string to ID the slices
function randomStringGenerator(length, chars) {
var result = '';
for (var i = length; i > 0; --i) result += chars[Math.round(Math.random() * (chars.length - 1))];
return result;
}
// get images function to iterate over the images saved to disk
(function getImage() {
// use 'setTimeout' to get around memory issues
setTimeout(function () {
// if there are more images than have been currently iterated through
if (imageCount > imageCounter) {
// path to current image to be sliced
var image = 'captures/' + images[imageCounter];
// use the size method to get the image width and height, useful for images submitted on mobile etc.
gm(image).size(function(err, value){
// check for errors, TO DO: put this in 'if' statement
console.log('Error: ', err);
// get current image width
var imageWidth = value.width;
// get current image height
var imageHeight = value.height;
// start slicing on first pixel
var sliceCounter = 1;
//
(function getSlices() {
// use 'setTimeout' to get around memory issues
setTimeout(function() {
// if the image height is bigger than the current slice
if (imageHeight > sliceCounter) {
// apply the random string to the slice name, time not needed here as it is in the parent image file name
var randomString = randomStringGenerator(32, '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ');
// crop image to the full width of current image and increments of 1 pixel
gm(image).crop(imageWidth, 1, sliceCounter, 0).write('slices/slice' + randomString + '.png', function (err) {
// check for errors, TO DO: put this in 'if' statement
console.log('Error: ', err);
// increase the slice counter, to affect the next slice
sliceCounter++;
// fire function recurssively, to help with memory
getSlices();
});
} else {
// if we have sliced the whole image, increase the 'imageCounter' to iterate over next image
imageCounter++;
// get next image
getImage();
}
}, 250);
})();
});
}
}, 250);
})();