A few scanning tips


Finding the Resample and
Scaling Menu Options

Photo editor programs vary in the name they call the resampling and scaling options. They don't make it very clear, and sometimes it's a real puzzle knowing what the options actually do. They seem to try to protect us by hiding the details, but for sure we don't know what to do then. Help files often ignore the subject, with changes" size" as the full depth of the description.

Several programs use a "Constrain File Size" or "Maintain File Size" option to switch the same "resize" dialog box between Resample mode and Scaling mode. This is the good way to do it. In the same way, the Photoshop or Elements resize dialog has a check box that directly says Resample, On or Off, and Off means "Scaling".


Scaling mode disables all options that allow changing the image size in pixels. The scaling option may be described as "Lets you change the image dimension or resolution but keep the file size the same". They don't ever say they are speaking only of printed inches, about the printed size and printed resolution, but they obviously are speaking only of printing size when file size and pixel dimensions stay the same.

Selecting "Constrain File Size" does not allow any change of image size in pixels. Therefore, it changes only the future printed resolution and size in inches. This is scaling. Change the resolution ppi and you will see the calculated size of printed inches change. Or usually you can change the printed dimension in inches, and it will then calculate the necessary resolution ppi to produce that printed size. The resolution ppi is the only value that is changed and stored, and the printed inches will track or follow on paper. Nothing at all visible happens until the image is printed at that size.

Repeating yet again (it is truly essential to understand this): Scaling does not change one single image pixel in any way whatsoever, and the file size therefore stays the same. What is changed is only the one resolution "number" that is saved away someplace, that indicates what resolution ppi should be used to space the pixels on paper when the image is printed. If printed with a lower number for ppi, the printed image size will increase in inches for example. This is because the number of pixels stayed the same, and ppi is "pixels per inch".


Resampling always changes the image size in pixels, and you see this new image size on the video screen immediately. The file size must change too, in order to store the different number of pixels. So to enter this resampling mode, we cannot use "Maintain File Size", we must turn that off so the file size can vary. We are allowed to change the image size in pixels, either directly, or by percentage. If we change the dimensions to 50%, it will be half size on the screen. This will also change printed size too, because if we reduce the pixel dimension to 50%, but still print those pixels at the same ppi, then it will print half size. We could change either the printing resolution or the printed size in inches, and since the other was not changed, the size in pixels must change to accommodate this relationship (We normally would not do that to print it, we would scale instead). This is resampling, and we see the pixel dimension change, the memory size change, and the file size change.

The resampling option normally provides a way to maintain or change Aspect Ratio, which is the ratio of image width and height. Sometimes this option is called Proportion or Distortion (meaning size distortion of proportion). Aspect Ratio normally should always be maintained constant (unchanged) when resampling photos, to prevent proportion distortion, but graphics are not always so concerned with constant aspect ratio. My point here is that this option to allow changing aspect ratio is disabled in Scaling mode, because it does not have meaning there, the pixels do not change.

If image size in pixels or size in bytes changes, then it is resampling. If not, it is scaling. Previous pages of this section discuss these modes.

Image programs vary. No one program does everything best, they each have different strengths and weaknesses, and you will likely use more than one. Each one handles printing differently. Sometimes the tools are rather strange, and hard to interpret. Simple programs typically do not offer scaling, but better image programs do provide a menu to set printing resolution. But it is not always clear.

This is the Adobe Image Size box:

resample  scaling

Resample Image selected - size changes do resample the image to create the necessary pixels for the print size specified, for example, the 6x4 inches at 300 dpi will resample to 1800x1200 pixels. Or, the pixel dimensions can be specified directly.

Resample Image NOT selected (or Constrain File size selected) is scaling, not resampling. The pixels are not affected in any way. Instead, new print size in inches is simply created from existing pixels to match the dpi specified.

Constrain Proportions - enter one dimension, and the other will automatically change to maintain the same aspect ratio, which is normally very desirable, otherwise disproportionate changes can distort the image shape. Instead, cropping is used to change the image shape to fit the print paper shape. See more.

Program Resample menu Scaling menu
Adobe PhotoDeluxe
(see HELP under "Photo Size")
Advanced - Size - Photo Size.

Constrain File Size NOT checked specifies Resample mode.

The same, but Scaling mode is when Constrain File Size is selected. Then set the desired resolution for printing, or set the width and height directly in inches.
Adobe Photoshop
and Elements
All versions
(see HELP under "Size and Image Resolution")
Image - Image Size

Selecting Resample Image selects Resample mode. Bicubic mode is best for photos, but not for graphics.

Image - Image Size

Scaling mode is selected if Resample Image is NOT selected. Specify either printed size OR the desired printing resolution.

Corel Photo-Paint
7, 9
Image - Resample
7.0 - Maintain File Size: Unchecked
9.0 - Maintain Original Size: Unchecked
Image - Resample
7.0 - Maintain File Size: Checked
9.0 - Maintain Original Size: Checked
Fractal Design Painter 5.0 (Corel now) Canvas - Resize
Constrain File Size Unchecked
Canvas - Resize
Constrain File Size Checked
IrfanView 3.97 Image - Size Image - Information - Resolution - Set
Or all options at File - Print will scale.
Micrographx Picture Publisher 8.0 Image - Size
Maintain File Size Unchecked is Resample mode.
Image - Size
Maintain File Size Checked is Scaling mode.
Microsoft Photo Editor 3.0 Image - Resize
Change width or height
File - Properties
Change print resolution
Microsoft Digital Image 10 Format - Resize Image
Lock Resolution, then change Pixels
Format - Resize Image
Lock Pixels, then change Resolution
Pagis Pro 3 Editor Page - Resize
Change width or height
Page - Change Resolution
Change print resolution
Paint Shop Pro
Version 4.14 and earlier
Image - Resample
Change the width or height in pixels.
File - Save As - Option - Dpi to be saved
This option is unique to every file type.
Paint Shop Pro
Versions 5,6,7
Image - Resize
Pixel Size or Percentage of Original will resample and change file size.
Image - Resize
Actual / Print Size will scale if you change dpi, and will not change file size.
CAUTION: If you change the size in inches here, it will resample instead.
Paint Shop Pro 8, 9, X
(Corel now)
Image - Resize
Resample should be Checked
Image - Resize
Resample should be Unchecked
PaperPort 6 Open with Page Viewer:
Page - Resize
Does not support scaling for printing.
PaperPort 10 Page Viewer: - Resize
Change Resolution is Checked.
Page Viewer: - Resize
Change Resolution is Unchecked
Picture Window 3.1 Transformation - Geometry - Resize
Preserve: Any choice except File Size
Transformation - Geometry - Resize
Preserve: File Size
Ulead iPhoto Express

(see HELP under "Size")

1.0   Photo - Resize - Size
3.0   Adjust - Resize
Change the size percent, or pixel Width or Height.
1.0   Photo - Resize - Density
3.0   Scaling is not supported
Change the print resolution. The new image size is previewed on the printer paper size selected.
Ulead PhotoImpact
Version 3 to 7
Format - Dimensions
Change the size percent, or Width or Height.
Format - Resolution
Change the User-Defined resolution dpi. The new image size is previewed on the printer paper size selected.
Ulead PhotoImpact
Versions 8, 10
Format - Image Size
Resample should be Checked
Format - Image Size
Resample should be Unchecked.

Copyright © 1997-2010 by Wayne Fulton - All rights are reserved.

Previous Main Next