How to concatenate two images?

Question

If I have two image files (eg. JPEGs) and I want to have one on the left side and one on the right side to make up one image, how do I do this?

Answer 1

In simple words, add the widths of the two images, then create a new canvas which has this sum as its width, and the highest height of the two original images as its height, then place the two original images side-by-side in this canvas.

In Paint.NET you can do it faster. You can simply expand the canvas (Image > Canvas size) of second image to the left to a width that's enough to accommodate first image (that is, the sum of two original widths), then just paste the first image in. If the height is not enough, Paint.NET will ask you whether to expand the canvas.

PhotoFiltre is even faster and can do such stitching automatically:

1. Open both images.
2. On any one image, click Edit > Copy.
3. On the other image, click Edit > Paste Special > Assemble.
4. Choose the desired direction and click OK.

Answer 2

AxB sized image1 and CxD sized image2. Create a A+C x B(if B>D, othervise D) sized image and copy image1 to 0;0 point, copy image2 to A;0 point with some image editing program.