How to combine images with the same dimensions in a grid?

Question

I have the following images, both 480 x 270 pixels:

I'd like to stitch them side by side in a 960 x 270 pixel image like so (scaled down):

So far, I've been using GraphicsGrid to try to achieve this:

c1 = Import["http://i.stack.imgur.com/2SRcD.png"];
c2 = Import["http://i.stack.imgur.com/zL8id.png"];
(* Frame parameter set here to emphasize next point. *)
g = GraphicsGrid[{{c1, c2}}, Frame -> True]

But there's padding between the images:

Additionally, it's scaled incorrectly, as ImageDimensions shows:

ImageDimensions@g

(* Expect {960, 540} *)
{360, 180}

I can use the ImageSize parameter to explicitly set the size of the output image, but that just reproduces the above result to scale.

How can combine the images side-by-side without scaling or padding?

Answer 1

What you're looking for is ImageAssemble:

c1 = Import["http://i.stack.imgur.com/2SRcD.png"];
c2 = Import["http://i.stack.imgur.com/zL8id.png"];
ImageAssemble[{c1, c2}]

It can also assemble vertically and horizontally:

ImageAssemble[{{c1, c1}, {c2, c2}}]

Answer 2

Incidentally, ImageDimensions on GraphicsGrid is behaving correctly. GraphicsGrid is generating an object with head Graphics, with a default width of 360 points, and the contents scaled down to fit. ImageDimensions then creates a bitmap version of the graphic, maintaining the size on screen, and returns the dimensions for that.