mosaic-node-generator-example

This is an example in order to show how to use the mosaic-node-generator module. See the README in order to learn how to use it.

Download and installation

First, you need to have installed the following:

• Node.js
• Git

Then, download the Github repo and install dependencies:

git clone https://github.com/Dellos7/mosaic-node-generator-example.git
cd mosaic-node-generator-example
npm install

Run the example

npm run mosaic

or

node index.js

When execution ends, you will have your generated mosaic image inside the outputs folder.

Results samples

Input image (input.jpg)

Outputs

Output using 100 rows and 100 columns as input and and 30x30 cell width and height (output_rc-100_30x30.jpg)

Code:

var mng = require('mosaic-node-generator');

mng.mosaic(
    'input.jpg',
    'pictures',
    30,
    30,
    100,
    100,
    null,
    'thumbnails_30',
    true
);

Output using 80 rows and 80 columns as input and 30x30 cell width and height (output_rc-80_30x30.jpg)

Code:

var mng = require('mosaic-node-generator');

mng.mosaic(
    'input.jpg',
    'pictures',
    30,
    30,
    80,
    80,
    null,
    'thumbnails_30',
    true
);

These examples write the generated thumbnails in the thumbnails_30 folder. Then we can use these thumbnails in following executions in order to improve speed. We can read the thumbnails directory using the utility like this:

var mng = require('mosaic-node-generator');

mng.mosaic(
    'input.jpg',
    'pictures',
    30,
    30,
    80,
    80,
    'thumbnails_30',
    null,
    true
);

Tips

• In the first execution, always write the generated thumbnails inside a folder. This is the 8th argument of the mosaic function. This is useful because it won't exceed the generatio of the mosaic image, as thumbnails will be generated after the mosaic image has been saved.
• In following executions, always read the thumbnails from the thumbnails folder generated in the 1st execution. You will see the speed increased a lot because what lasts more is the pictures read, specially if pictures are heavy and you have a lot.
• Do not generate a mosaic using too much rows and columns. This will cause the generated image save to fail due to Node.js memory leaks. I wouldn't recommend using more than 100-120 rows and columns.
• If you are generating the mosaic using a thumbnails folder, make sure the thumbnails are the same size as the input cell width and height.