How can save an image without matlab altering any of the images's property

I need to save an image i displayed in an axes, am doing so currently with the 'getimage' function. But it seems to be changing the image pixel values when i save, is there another function i can use that doesn't alter the image in any way?

Answer 1

[Image Analyst]

You only get changed pixel values if you save the image with a lossy compression format like JPEG. To avoid that, save the image in a format that does not use lossy compression. For example, use PNG (which uses lossless compression) and a call to imwrite():

imwrite(rgbImage, 'myImage.png');

However that will not save any EXIF or IPTC metadata that was stored along with your original image file, nor will it preserve the file date.

Answer 2

[Stalin Samuel]

• Read the image using imread
• ex. I=imread('test.jpg');
• Now the image pixel values available in the variable I
• Otherwise you can permanently store the image in the directory as mat file
• To save as mat file use 'save I'
• Then later whenever the image is required use 'load I ' to load the image into workspace

Answer 3

[Walter Roberson]

If you are creating a pseudocolor image and want to save it, then I recommend you look in the File Exchange for the freezeColors contribution. You would call that and then you could get() the CData property of the image handle and the result would be an RGB image equivalent to the displayed pseudocolor image. You can then imwrite() that using a lossless format such as PNG or TIFF.