Thumbnails from graphics magick without upscaling

Question

I am using the graphics magick wrapper in nodejs and am creating square thumbnails using the following code:

var size = {width: 200, height: 200};
gm(sourcePath)
  .resize(size.width * 2, (size.height * 2) + '')
  .thumbnail(size.width, size.height + '^')
  .gravity('center')
  .extent(size.width, size.height)
  .profile('*')
  .write(outputPath, function (error) {
    if (error) console.log('Error - ', error);
  });

This works nicely, until the size of my thumbnail is bigger that the input image. In this case I would like the thumbnail to be the size prescribed, but for the image to be placed in the center of it rather than resized.

Is there a way to do this with a group of commands or do I have to write some separate logic to determine that?

Answer 1

I ended up using GM directly for this using this command:

gm convert inputPath -resize "200x200>" -gravity center -extent 200x200 outputPath

This will create an image 200x200 with the input image centered in it, they -resize 200x200> part (note the >) means only resize it to be smaller not bigger

The equivalent command using the gm module in node is:

var size = {width: 200, height: 200};
gm(sourcePath)
  .resize(size.width, size.height + ">")
  .gravity('Center')
  .extent(size.width, size.height)
  .write(outputPath, function (error) {
    if (error) console.log('Error - ', error);
  });