I have 3 pictures with different dimensions. I want to decrease the size of these pictures without stretching them. I have used content aware with photoshop but it doesn’t work as i have 200X842 dimension which is quite small. Is there any solution to this?
Content-aware scaling works by using a process called seam carving, which relies upon being able to compress/stretch some parts of an image while protecting others. For images that have complex backgrounds, automatic seam carving will likely fail, or just not work very well.
To get a better result in Photoshop for an image like your example, which has a lot of detail in the background, you need to create an alpha channel which you can use to protect specific areas of the image when using Content-Aware scaling.
Basically, use the Quick Select tool to roughly select some areas to protect
Then add an alpha channel in the channels panel by clicking on the Mask button, to save the selection as an Alpha Channel.
Select the RGB channel, go back to the Layers Panel, Select > Deselect. Select the image layer in the layers panel. And do Edit > Content Aware Scale
In the tool options along the top, set the Protect drop down to the Alpha channel you made previously
Now Content-Aware scaling will work nicely
Once you have achieved the desired aspect ratio, then you can crop the leftover edge, and scale the image to the size you want using Image > Image Size. Make sure to engage the aspect ratio lock before entering the new size. Obviously if you are reducing the image size, make sure to also choose the Bicubic Sharper (Reduction) algorithm.