Scanning Tips

Comparing a "low resolution" scan to a "higher resolution" scan

Low Resolution Scan

     This photo was scanned at a low resolution and when zoomed in, pixelation is seen.

High Resolution Scan

     This photo was scanned at a higher resolutionand when zoomed in, no pixelation is seen.

Can I Increase the Resolution of My Photograph?

• The answer would be "Yes" in most cases. Photoediting software allows you to change the dimensions (or resolution) of an image.
• The software uses artificial intelligence to try to fill in more pixels where it thinks they should go. For the most part, doubling the resolution works pretty well. For small resolution photos however, you will have difficulty going past doubling the resolution.
• Increasing the resolution of an image may also introduce some extra artifact like around objects in the image. These can often be reduced though using other photoediting techniques.

How Can I Tell What Resolution My Photo Is?

     First notice that this photo is wider than it is tall. It is considered to be a "Landscape" photo.

     Next, right click on the filename and select "Properties" from the menu list. A dialog box will open and then click on the "Details" tab. Scroll down to the "Image" section. Notice that the photo Width of the photo is 1290 pixels and the photo height is 953 pixels. The photo is still a bit small to be printable with good quality.

     If a printer prints at 300 dpi, the resulting image would print out a 4.3" X 3.2" image size. Trying to force the image to fit onto a 4" X 6" paper size would result in a pixelated image.

     Remember, to print a landscape view photo to a 6"W X 4"H paper printout, your minimal image size needs to be 1800 pixels in width and 1200 pixels in height.

     First notice that this photo is taller than it is wide. It is considered to be a "Portrait Mode" photo.

     Next, right click on the filename and select "Properties" from the menu list. A dialog box will open and then click on the "Details" tab. Scroll down to the "Image" section. Notice that the photo width of the photo is 252 pixels and the photo height is 342 pixels. This would be considered a very small photo.

     If a printer prints at 300 dpi, the resulting image would print out a 0.84" X 1.14" image size. Trying to force the image to fit onto a 4" X6" paper size would result in a pixelated image.

     Remember, to print a portrait view photo to a 4"W X 6"H paper printout, your minimal image size needs to be 1200 pixels in width and 1800 pixels in height.

Definitions

• DPI: short for dots per inch, also sometimes referred to as PPI or pixels per inch. Represents how many photo pixels are found in 1" of screenspace.
• Resolution: refers to the number of pixels that exist within that image. For example, if an image is 500 pixels wide by 500 pixels long, there would be 250,000 pixels in that image. If an image is 5,000 pixels wide by 5,000 pixels long, then there are 25,000,000 pixels in that image. The 2nd image is much larger or higher in resolution than the 1st image.
       On a Windows PC, RESOLUTION is noted as DIMENSIONS instead when looking at the image properties. However,the official terminolgy is RESOLUTION.

Displaying Images on Monitor & TV Screens

• Think of a "high definition" monitor, the most common monitor type stlll out there, also called 1080P. This monitor can display 1,920 pixels across and 1,080 pixles down. An image with 1000 pixels wide by 500 pixels down would display on that monitor just a little over half the monitor size.
• As technology has improved, the abilty to display more pixels on a screen has immproved. Today, we are seeing more commonly "4K" monitors and TV screens. These screens can display 3,840 pixels across and 2,160 pixels down, basically double the size. That same 1000 pixel by 500 pixel image above, when displayed on this 4K screen would only display on about a quarter of the screen.

How Does "dpi" (dots per inch) Relate to Scanning and Printing Images?

• When thinking about dpi, this really only relates to to the SCANNER, and NOT to the digital images themselves. It also relates to the pixel resolution of monitor. For example, typical Full High Definition monitors have a 72x72 dpi resolution, while those of Apple & other higher end monitors have a resolution of 144x144 dpi. An image on these higher end monitors would display at ½ the size, as it would display on an Full HD monitor.
• Scanners have to convert a physical image into a digital one. The dpi is requested to give some degree of control over this conversion process. The higher the dpi, the greater the horizonatal and vertical dimensions of the digital image will be in pixels.
• You only need to worry about dpi settings when you are working with the scanner. It is the way that the scanner knows what size of photos you are scanning, and what the output resolution will be.
• Important Point: We use DPI to help the scanner know what image size or RESOLUTION we want to scan to.
• Scanning a 6"W by 4"H photograph at 300 dpi would result in an image being 1800 pixels in width and 1200 pixels in height.
• Scanning a 6"W by 4"H photograph at 600 dpi would result in an image being 3600 pixels in width and 2400 pixels in height, or doubling the size of the photo.
  If you wanted to print this to 10" by 8" paper, would the image resolution still be okay? Calculate it out. You need a minimum of 300 X 10 or 3000 pixels for the width to get good quality, so the scanned image resolution is fine.
• Scanning a 6"W by 4"H photograph at 1200 dpi would result in an image being 7200 pixels in width and 4800 pixels in height, or quadrupling the size of the photo. This would be significant unnecessary overkill for this photo size, UNLESS you were wanting to print it to a 24" by 16" paper size.
• Important Point: Scanning at too high of dpi settings can create unnecessarily large image sizes and also may introduce image artifacts from the paper, dust, scrateches, and such. If you ever want to print out images, just remember that a standard photo printer prints at 300 dpi. If you want to print to a large 8"W by 10"H paper size, you simply multiple the paper size 8"X10"(portrait view) times 300. Your minimum image resolution would be 2400 by 3000. That's really all the resolution you would need to print a good quality print!