I took a landscape photo in portrait orientation. Now, when I rotate the picture into correct orientation, it looks smaller than the original sideways image. I want to maintain its original height and width.
Based on Anisha's verification, The question can be summarised as:
A number of "solutions" are provided below.
4:3 ratio picture
Any other screen and image ratio can be assumed.
"Took a landscape photo vertically" is assumed to mean that the camera was held in portrait orientation to take the photo / long axis vertical / 4 tall, 3 wide.
When the photos were presented to you they presumably were in landscape mode, long acis hozizontal, so that the photo was "on its side". The photo could be fitted to fill a 4:3 display (4 wide, 3 high.)
Now the fun begins.
As the image height fits the screen height it's area as a % of screen area is 56.25% of screen area.
You cannot make the image taller without some of it being above screen dimensions.
The image looks small because it IS small compared to available screen size. It is only 56.25% as large area wise as an image that fits the screen "properly".
Note that if you print this image and display it in portrait mode, as it was taken, then it will be as large as a landscape image printed full size on the same size paper - it is only a screen problem.
There are various things you can do about this depending on how serious you are.
Anisha confirms that the problem being addressed above is indeed the problem that they want solved.
Anish - If Drewbenn described you problem exactly then my answer tells you a number of ways to "solve" it. None are ideal, but arguably the best one is to realise that this is an effect that is unavoidable with a minitor of a fixed size, and that taking pictures in landscape mode is necessary if you want to view them fully filling the sceen. The coices are to fit the heightm abd have empty area either side, or to fill the width, nand then crop top and/or bottom.
This isn't an answer, just an attempt to clarify the question, and I need the space that an "answer" provides. Is this what you're seeing? If not, you may need to share the exact list of steps that you're taking (run program X. Go to File menu, select Open, browse to the image I want, select OK. Go to Edit menu, select Rotate.....) to get a useful answer.
Here I'm looking at my image "normally" in my image viewer. The image viewer is displaying a 3:2 aspect ratio image in a window set up for a landscape image; you can see that the picture takes up the full height of the viewing area but not the full width, although it almost fills the width of the canvas. In the status bar, you can see that the image is scaled to 23% of its original size (if I was viewing it at full size, that number would be 100%).
Okay, now I went to Image | Rotate Clockwise, and the image has been rotated. My image viewer program hasn't resized itself, and is now trying to fit the image, with a 2:3 aspect ratio, inside the same landscape canvas. The image still takes up the full height in the canvas, but only a small fraction of the width. If you look at the status bar, you see that the image is now scaled to only 15% of its original size:
The image resolution hasn't changed (just been reversed from 3504x2336 to 2336x3504, as you can see in the status bar in each screenshot). The only thing that has changed is the amount of room that the image viewer has available to fit the picture onto the screen, so the image viewer has rescaled the image to fit in the provided canvas.
Some pictures like this (taken with a medium format camera):
have a square form factor, and will by definition have the same scale if rotated. What you can do is to crop your picture to a square (of course you will lose parts of the image) or even to a landscape format. But for portrait pictures the first option may be more appropriate (or maybe less inappropriate).
But since your screen is wider than tall, landscape format will always appear bigger.