Why is printer reducing scanned images?

[Pete2635]

I am scanning  an image that I simply want to print at 100%, but when I print the size of the image is reduced by  about 30%.Why the F is this happening and what can I do to just get a 100% copy?!

[Pete2635]

 None of the screens or instructions shared matched what I experienced while going through the process. My HP Envy Scan software doesn't look anything like what's shown here. Here's what happened. 1.  After guessing my way through and going through a series of steps not described in the answer, I finally found the "download full drivers" choice. I downloaded and the file installed but it did not open. 3. Instead was taken to the place to  install "HP Easy Access" (or HP Easy Install, or whatever it's called) software which I had already downloaded 3 times when having earlier problems with the printer. It ran me through a whole new device installation process. 4. After that reinstallation, I was again requested to download drivers, through a whole different screen, so I did. 5. After download was complete, Instead of getting the usual "Open" notification through Windows, I got an HP message that said "Find your File Here," with no file specified and nothing to click. I located the "Full WebPack" exe file in my downloads folder and clicked to open/run. No application  opened. 6. Thinking that the application might have updated, I clicked my "HP Envy Scan" icon and got the same, very basic, print screed I've always had in that program. (Nothing like the screens in the above answer.) What do I do now?

[Pete2635]

I restarted the computer and printer, found the exe file again and ran "as administrator." When the program opened, it gave me the option of either device "Envy 7855" or "HP AI0 Scanner." I tried one, then the other, but still got the same old basic "HP Envy Scan" screen with  none of the details or options illustrated in the above answer.

[Pete2635]

I never see the Print screen pictured in the answer.

[Pete2635 · Accepted solution]

Solution. I was using the HP Scan program to scan;  after switching to use HP Smart for scanning, the images printed normally at 100%. The reason for using Scan, though, is that it gives options for adjusting the scan for brightness, contrast and midtone while Smart does not. The midtone is not available in Smart or in Windows Image, and is especially useful for scanning old black and white photos or printed black and white images, which I do a lot of. HP is stumped as to why Scan was automatically reducing images when printing. I have had so many problems with the Envy 7800 (It loses the connection weekly even though I'm connected through USB, for example) I am probably going to risk upgrading to a new Office Jet product. I hope there is better support and fewer glitches with them.