There are different size of images in a folder, I need to combine them into one large image. I'm trying to implement it with html5. Any idea how to fill all the images into a fixed width canvas (1980px) without scaling the images?

Here are the conditions:

• The canvas width is 1980px and canvas height needs to be auto increased which depends on images' amount and height.

• The images can't be scaled.

• After images filled in, the white space of the canvas must as little as possible. Each image size needs to be detected and put it in a right position.

• The minimum merging of each image is 5px.