ThumbNails

User Guide — Mapsoft ThumbNails Plugin for Adobe Acrobat — version 1.6.2

Overview

Mapsoft ThumbNails is an Adobe Acrobat plug-in produced by Mapsoft Computer Services Limited. It saves the pages of a PDF document as image files, for web pages and online shops, catalogues, document previews, presentations or records. You choose the resolution, the image format, the folder to save into and a prefix for the file names, and can draw a coloured border around each image.

ThumbNails can save every page, a range of pages, the current page, or just the odd or even pages. Its settings can be saved under a name, to be used again in ThumbNails or in a batch with Mapsoft Acrobatch.

ThumbNails is free: it needs no licence or activation.

System Requirements

Microsoft Windows 10 or 11
Adobe Acrobat Standard or Pro, 32-bit or 64-bit (not Acrobat Reader)
Protected Mode: supported. ThumbNails runs with Acrobat’s Protected Mode switched on and does not require it to be disabled.

Opening ThumbNails

Open the PDF document in Acrobat and choose Plug-ins > Mapsoft > ThumbNails…. ThumbNails works on the document you have open, so the command is unavailable when no document is open.

Note: In Acrobat 2023 and later the menu bar is hidden by default. Click the Menu button at the top left of the Acrobat window and choose Plug-ins > Mapsoft > ThumbNails….

The dialog opens with its standard settings each time. To reuse settings, save them as a configuration (see Name Configuration).

The ThumbNails Dialog

Image Settings

Setting	Description
Resolution of output images	The resolution of the images in dots per inch, from 1 to 2400. The default is 72, at which a US Letter page (8.5 × 11 inches) becomes an image of 612 × 792 pixels; at 144 dpi the same page is 1224 × 1584 pixels.
Save to	The folder the images are saved into. Click Browse… to choose it. The folder must already exist.
Prefix	The start of every file name (`img` by default). See Image File Names.
Format	The image format (see Image Formats).

Border

Tick Create border around images to draw a frame around each image. Click the colour button beside it to choose the colour (black by default), and enter the line width in pixels (at least 1). The border is drawn inside the edges of the image, over the page, so the image stays the same size. The border is not ticked when the dialog opens.

Page Range

Option	Description
All pages (the default)	Every page of the document is saved.
Specified pages only	Only the pages listed in the box beneath are saved (see Page Range Syntax). Clicking in the box selects this option. A range you have typed is kept if you switch back to All pages.
Current button	Fills in the number of the page currently displayed in Acrobat and selects Specified pages only.

Page Spread

The Page spread group restricts the pages saved to the odd or even pages within the page range:

Option	Description
Odd and even pages	Every page in the range is saved (the default).
Odd pages only	Only odd-numbered pages in the range are saved.
Even pages only	Only even-numbered pages in the range are saved.

Name Configuration

A configuration is a named copy of all the settings in the dialog: resolution, folder, prefix, format, border, page range and page spread. Saved configurations can be used again in ThumbNails and in Mapsoft Acrobatch.

Control	Description
Configuration drop-down	Choose a saved configuration to load its settings, or type a new name. Names may contain the letters A–Z (without accents), digits, spaces and most punctuation, but not `\`, `[`, `]` or `. Avoid commas, which Acrobatch uses to separate names.
Save	Saves the current settings under the name shown. If you typed the name of a configuration that already exists, you are asked before it is overwritten; a configuration chosen from the drop-down is updated without asking. The settings are checked first (see Messages), so the output folder must exist. Saving does not create any images.
Remove	Deletes the configuration chosen in the drop-down.

Configurations are stored in the Windows registry for your user account and persist between Acrobat sessions.

Buttons

Button	Action
OK	Checks the settings, saves the selected pages of the current document as images and closes the dialog. If a setting is not valid, a message says what to correct and the dialog stays open.
Cancel	Closes the dialog without saving any images. A configuration you saved is kept.
Help…	Opens this user guide in your web browser.

Hover over any control in the dialog for a short description of what it does.

Step-by-Step: Saving Pages as Images

Open the PDF document in Adobe Acrobat.
Choose Plug-ins > Mapsoft > ThumbNails….
Enter the Resolution of output images.
Click Browse… and choose the folder to save into.
Enter a Prefix and choose the Format.
Optionally tick Create border around images and choose its colour and width.
Choose the Page range and Page spread.
Optionally type a name and click Save to keep the settings for later.
Click OK. The images appear in the folder you chose.

To use a saved configuration, open ThumbNails, select the configuration from the drop-down and click OK.

What the Images Show

Each image shows its page as Acrobat displays it:

Turned as on screen: a page that Acrobat shows rotated (by 90°, 180° or 270°) is saved the same way round, so a landscape page shown sideways gives a landscape image.
Cut to the visible area: the image covers the page’s crop box, the area Acrobat shows, so a page cropped in Acrobat is saved cropped.
Comments and form fields are included as they appear on the page.
Background: areas of the page with nothing on them are white, and every image is fully opaque.

Image Formats

Format	Extension	Notes
JPEG (the default)	`.jpg`	Compact; best for photographs and for web pages.
PNG	`.png`	Lossless; best for text and line art.
DIB	`.dib`	A Windows bitmap (the same as BMP) with the `.dib` extension, for software that expects it.
TIFF	`.tif`	Lossless; widely used in print and publishing.
BMP	`.bmp`	Uncompressed Windows bitmap.
GIF	`.gif`	Reduced to 256 colours; suits simple pages, not photographs.

Image File Names

Each image is named with the prefix followed by a six-digit page number and the format’s extension, and saved in the folder you chose. The number counts from 0 and is hexadecimal (it uses the digits 0–9 and then the letters a–f):

Page	File name (prefix `img`, PNG)
1	`img000000.png`
2	`img000001.png`
10	`img000009.png`
11	`img00000a.png`
16	`img00000f.png`
17	`img000010.png`
100	`img000063.png`

Only the selected pages are saved, and each keeps its own number: saving pages 2 and 3 gives img000001.png and img000002.png.

Note: An image that already exists with the same name is replaced without asking. Saving a second document into the same folder with the same prefix therefore replaces the first document’s images. Give each document its own prefix or folder. Images in other formats are not affected: saving JPEG images leaves PNG images of the same name alone.

Page Range Syntax

When Specified pages only is selected, enter a comma-separated list of page numbers or ranges:

Example	Meaning
`5`	Page 5 only
`6, 12, 15`	Pages 6, 12 and 15
`3-19`	Pages 3 to 19
`-28`	Pages 1 to 28
`3-`	Page 3 to the last page
`3, 8-10, 14, 18`	Pages 3, 8, 9, 10, 14 and 18

Spaces around commas and hyphens are ignored, and ranges may overlap. Page numbers start at 1. Separate page numbers with commas: 1 5 or 3;5 is reported as not valid. Pages beyond the end of the document are ignored. Write each range lowest page first (5-10): 10-5 contains no pages, so on its own it saves nothing.

The page spread applies within the range: -10 with Even pages only saves pages 2, 4, 6, 8 and 10.

Messages

When you click OK or Save

ThumbNails checks the settings first. If one is not valid it says so, nothing is saved, and the dialog stays open for you to correct it:

Message	What to do
Please provide a folder for image output.	Choose the folder with Browse….
The specified folder can not be found.	The folder has been moved or deleted: choose another.
Please specify a prefix that will be applied to each thumbnail image.	Enter a prefix.
Please enter an image resolution between 1 and 2400 dpi.	Correct the resolution.
Please enter a border line width of at least 1 pixel.	Enter a width, or untick the border.
The page range is not valid!	Correct the page range (see Page Range Syntax).

While saving the images

Message	Meaning
No pages in the document match the page range and page spread, so no thumbnail images were created.	For example, a range beyond the last page, or Even pages only with a range of odd pages.
N thumbnail image(s) could not be saved to folder.	The other pages were saved. Check that you may write to the folder and that the disk has room. A very high resolution can also make an image too large to create: no side of an image can exceed 32,767 pixels (about 13.6 inches at 2400 dpi).
Failed to create thumbnails.	Acrobat reported an error while reading the document; the pages already saved are kept.

Saving Images from Many Documents

ThumbNails works on the current document. To save images from many documents in one operation, save a configuration and run it from Mapsoft Acrobatch, alone or together with other Mapsoft plug-ins. The configuration is applied exactly as it would be from the dialog, and any problem (a configuration that no longer exists, a setting that is not valid, pages that could not be saved) is written to the Acrobatch log instead of being shown on screen.

When you set up the step in Acrobatch, the ThumbNails dialog opens for you to choose or create the configuration. In this case its OK button is unavailable and Cancel reads Close: the dialog only chooses the configuration.

Tip: Because the file names come from the page numbers, give each document its own output folder or prefix in a batch, or the images of one document replace those of the one before.

Tips and Notes

Choosing a resolution: 72–96 dpi suits small previews and web thumbnails, 150 dpi on-screen reading, and 300 dpi or more printing. Image size, and the time taken, grow with the square of the resolution.
Your document is not changed: ThumbNails only reads the document; it does not add, embed or remove anything in it.
Protected Mode: with Acrobat’s Protected Mode on, ThumbNails makes each image in a temporary folder and the Mapsoft broker, which the installer adds to Acrobat, copies it to your folder. Reinstall ThumbNails if images are reported as not saved only while Protected Mode is on.
Free: ThumbNails needs no serial number and adds nothing to your images.

Support

If you encounter a problem or have a question not covered here, please get in touch: