If you are download from blogspot, please grab the images from the higher res image sources.
For example, the normal image linked to on blogspot is https://1.bp.blogspot.com/-sKxIZ-FjpS4/XPfU8w0rcFI/AAAAAAAADwo/Y_LD2vEW268_9ku1dIi7MZBauepBVVcMQCLcBGAs/s1600/spookwallghost.png <-- this gallery includes this image
But you can change the url to https://1.bp.blogspot.com/-sKxIZ-FjpS4/XPfU8w0rcFI/AAAAAAAADwo/Y_LD2vEW268_9ku1dIi7MZBauepBVVcMQCLcBGAs/s2560/spookwallghost.png <-- but this version is better quality
note the "s1600" and "s2560" lines, denoting the resolution of the images. I think s2560 is the highest resolution, at least I could not find a higher one (I could be wrong). This gallery currently has the normal, "s1600" images, which are not the original resolution images.
There might be browser addons that automatically do this, I did not check.