CollectionFS Graphicsmagick resize width only if larger than

Question

On collectionfs I have following method to resize large images to width of 1200px and height remains proportional in order to reduce file size.

var createPic = function(fileObj, readStream, writeStream) {
    gm(readStream, fileObj.name()).resize(1200).quality(100).autoOrient().stream().pipe(writeStream);
}

Images with lets say 2000x2000 dimension actually end up uploaded 1200x1200 but larger in file size. Can you explain why? And how can I modify the method to only resize image if width exceeds for example 2000px?

Also, does anyone know how much facebook reduces photos in size and quality? Or do they use some kind of algorithm depending on image? — Zaya
That didn't resize at all and more than doubled the image file size. original image is 1919x1919 1.3mb. I had 1200x1200 1.8mb. With your guess it is 1919x1919 2.9mb — Zaya
1200x1200 1.8mb. Can you explain the second argument. I assume this is the height. — Zaya

Menda Menda · Accepted Answer · 2016-05-13T10:22:03

This works:

gm(readStream, fileObj.name()).resize(1200, 1200, '>').quality(100).autoOrient().stream().pipe(writeStream);

However, after using it with the gridfs package you may get this error: Error: <ID> does not exist. This is a package's bug, so this topic would go separately.

CollectionFS Graphicsmagick resize width only if larger than

1 Answers