How to increase number of rows and cols without changing the image size?

Is there a function to increase the number of rows and cols without changing the image size?

Example: I have an image that is 301X301 with pixel size 1mm. How do I increase the number of pixels to 1024X1024 with pixel size (301/1024)mm? Effectively maintaining the image size.

imresize only change the number of pixels, not pixel size. Am i right?

Answer 1

[Image Analyst]

That's correct. How big you consider a pixel to be in "real world units" depends on the calibration you're using. It could be one micron, one kilometer, or one light year. If I have a length that is 1 meter long in MATLAB, and it happens to be 1000 pixels long, then I can multiply the number ob pixels by 1/1000 to get the distance in meters. If I resize the image so that that length is now 2000 pixels long, then my calibration factor will have to be 1/2000 now in order to still get a real world distance of one meter again.

[Yun Inn]

I know for sure that the 'real world' pixel size is 1mm and I want the new pixel size to be 0.29mm, can i specify that without performing actual calibration?

I would like to do the following: # Imresize (data, (1024/301)) # Reduce pixel size from 1mm to 0.29mm

[Image Analyst]

You can't do that. The distance between landmarks in your scene is fixed. For example, if the distance between one edge of a hair and the other edge is 100 microns, you can't just declare it will be 290 microns, because it isn't 290 microns - the hair is still 100 microns wide. All you can do is to change the number of pixels that go between that distance.