Have you tried the Abobe ACR Super Resolution yet? It is awesome! It increases the pixel count 400%
Enhance allows you to increase image quality for making large prints or increasing the resolution of a cropped image.
I compared Abobe ACR Super Resolution to Topaz Gigapixel, which I have used in the past and it works, but it is clunky and slow. Workflow wise Topaz Gigapixel does not interpret RAW files well, so I have to open the file in ACR and save it as a TIFF and then open it in Topaz Gigapixel, takes a while to process. Six comparisons are herein.
The new Abobe ACR Super Resolution is easy -- built right into ACR (right click and click enhance and check Super resolution) and it creates a dng file.
Note: Starting with Adobe Camera Raw 13.2 (March 2021 release), Enhance Details is renamed to Raw Details.
Enhance provides a set of features such as Raw Details and Super Resolution to help improve image quality using Camera Raw.
Raw Details, previously called Enhance Details produces crisp detail and more accurate renditions of edges, improves color rendering, and also reduces artifacts. The resolution of the enhanced image stays the same as the original image. This feature is especially useful for large displays and prints, where fine details are visible. The supported file types are raw files.
Super Resolution, introduced in Camera Raw 13.2, helps create an enhanced image with similar results as Raw Details but with 2x the linear resolution. This means that the enhanced image will have 2x the width and 2x the height of the original image, or 4x the total pixel count. This feature supports the same file types as Raw Details, plus additional file types such as JPEG and TIFF. Super Resolution is especially useful to increase the resolution of a cropped image.
When you click super res you will see it processing and end up with a Digital Negative (DNG) RAW file. FYI, any edits/adjustments that you made to the source photo will automatically be applied to the enhanced DNG and you can edit the enhanced DNG just like any other photo.
How to use and find Super Resolution.
FYI, Right now it is only in ACR (Adobe Camera RAW) and not accessible via the filter camera RAW. It is coming to Lightroom soon. You can use Super Resolution on a JPG file, you just need to make sure that your ACR is set to open JPGs (see Figure5 below)
Figure 1. Open your RAW or JPG file in ACR (when you open a RAW file in Photoshop it automatically opens in ACR, but for a JPG file to open in ACR you must change a file handling setting, sett Figure 5). Right click (PC, or Control click MAC) and then select Enhance (PC shortcut Ctrl Sh D).