zooming in on a part of a video or photo

[snafubaby]

I am looking for the best method to use in order to zoom in on a frame of a particular photo or video. I would imagine it would depend on the quality of the video or photo to actually get an acceptible zoomed shot. Does anyone out there on this website have any good experience with this sort of thing, who might wanna give me some tips on how to do this? Wanna recommend some good software? I know that there is a zoom filter for virtualdub out there. Does it do an adequate job of zooming in on a photo or video? Could i get a high quality result with a particular piece of software? Any help would be appreciated.

[hello_hello]

It should be easy enough to do with almost any video encoder. If you take (as an example) a standard 720p video (1280x720) and remove some of the picture from the top, bottom and sides (cropping) then resize it back to 1280x720, you've effectively zoomed in. The trick is to know how much to crop so when you resize it you're not distorting the picture.... assuming you want to resize it back to the original dimensions. How it'll be resized depend on the resizer you're using. Some resizers are sharper than others, and it's generally a compromise between blurriness and resizing artefacts.

If you're just wanting to take a frame of a video, save it as an image and crop and resize it (effectively zooming) it's easy enough to do using MPC-HC and Irfanview. Just open the video using MPC-HC, pause it on the frame in question and use the File menu to save it as an image. You'd probably save it as a bitmap as it's a lossless format. Open it with Irfanview and click on the image somewhere and drag the cursor to select a section of it. You can then use the mouse to move the borders of the selected area. When you've selected the area you want to keep, use the "Edit/Crop Selection" menu. From there you'd use the Image/Resize/Resample menu to enlarge it. There's a few different resizing methods to choose from in the window which opens. If you make sure the "preserve aspect ratio" box is checked, you won't distort the picture while resizing by a specified percentage or to a specified width or height in pixels. Irfanview can then save the resized image as a jpeg or using several other image formats.

There's also an exe containing a plugins package on the Irfanview site which is worth downloading and installing once Irfanview is installed. Thinking about it, Irfanview can also open many types of video. Under the Options menu, there's one to extract a range of frames as bitmaps.