Hi manoj thanks for reply, I can explain what was the wrong, and i have fixed it from other way. let you know why its showing always 300x45px. while Im uploading new logo after select that logo its asking crop that image and i cant skip that option so when i crop that image its auto crop with 300x45px and you can that crop image size in your folder by opening control panel. and image name will rename as a crop-<here old img name>
and this image will link there in logo area that means logo size will be alws 300x45px and if I change image height and width from code that means only 300x45px image will resize so in this condition image will come with bad resolution.
Now for my solution I crop image and i open my cpanel and delete that crop<here old img name> and give original img file name as a crop img name so now I can get high resolution img in my logo and also i can change height and width
