Very Large Bitmap Viewer Manual
Copyright 2013, Artwork Conversion Software, Inc.
Table of ContentsIntroduction
Measuring with the Ruler
Pan & Zoom with Mouse/Keyboard Controls
VLBV (Very Large Bitmap Viewer) was developed by Artwork to solve a problem we had in testing our high resolution rasterizers. We needed a viewer that could handle GByte TIF monochrome (BW) files - tools such as Photoshop and other bitmap programs could not handle such large files.
We also needed a viewer that could handle very large monochrome BMP files - something that most Windows tools have problems with due to their use of libraries that are limited to 32 bit memory operations.
We finally wrote our own monochrome bitmap viewer designed specifically to handle these large files:
a) native 64 bit Windows;address as much memory as can be loaded onto a workstation
b) support monochrome BMP up to the file format limit of 4 GB.
c) compresses data into memory for small footprint
d) fast zoom in/out and pan
e) measurement tool
f) overlay two files with transparency (not implemented in v1.03)
Drop Down Menu
File | Open
Use this to get to the File Open dialog. Four types of files are supported:
BMP (monochrome: no compression)
RAW (raw bitmap)
LG RAW (raw bitmap with custom header for LGE)
A RAW bitmap is one with no header. Each bit represents a pixel. In order to display such a file, the viewer must be instructed by the user the number of pixels in a row -- i.e. the width of the image.
The row data may be: a) not aligned to bytes/words, b) aligned to byte boundaries c) aligned to word boundaries
You should select the correct option or your display will be incorrect.
File | Info
provides a summary of the bitmap characteristics.
View | Home
Zooms the display to the full extents of the data. Shortcut Key = R
View | Redraw
Forces a screen redraw. Shortcut Key = H
View | Zoom In
Zooms in the display by 2X. Focus shifts to the display where the user must left click with the mouse.
View | Zoom Out
Zooms Out the display by 2X. Focus shifts to the display where the user must left click with the mouse.
View | Zoom Window
Enables the user to define a window (using the mouse) to zoom into.
View | Pan
Switches to the pan tool and enables the user to pan by click/drag of the mouse.
View | Previous View
goes back to the "previous" display. (Several levels are cached so this is quite fast)
View | Next View
Only active if a previous view has been selected. Goes to the view stored prior to the previous view. Cached; so very fast.
Preferences | Status Bar
If checked, a status bar across the bottom of the display will be visible. The coordinates of the cursor are updated. Measurement information is also presented in the status bar.
Preferences | Load Mode
Controls how VLBV loads the data for display.
Bitmap data is read from disk, compressed and saved in memory. The intial display and any change in display window results in a call to memory and extraction of the required pixels. For large files, the load time (due to compression) can be very significant but panning and zooming after that are fast.
If this option is set, the bitmap data is read and directly converted into display. This mode will show the initial view the fastest. However each change in the display causes a new read from disk. This could be a useful option if you have the bitmap data stored on a fast solid state drive.
Load2MEM in Background
If this option is set, the bitmap data is read directly to the display and a second process loads it into memory in the background. Initially, changes in display trigger a read from disk until the load to memory is completed. After that time, all changes in display read from memory.
Help | Web Page
Links to the VLBV Web page at www.artwork.com
Help | Viewer Help
Opens the user manual (HTML)
Help | About
Displays the version and license information
Help | License
displays license information
The VLBV Toolbar
Measuring with the Ruler
The ruler enables the user to measure the distance between two pixel locations. To use the ruler, first select it from the toolbar. The click on a location with the right mouse button. Now move the cursor to the second location and click with the left mouse button.
The X,Y and total distance between the two points will be displayed in the status bar.
To make a precise measurement over a large distance it is possible to zoom in, click, zoom out and then pan, then zoom in a again and make the second click.
Pan and Zoom using Mouse Controls
VLBV was designed to make pan and zoom quick and efficient using the mouse. We recommend a 3 button mouse with the middle button a scroll wheel.
Pan - hold the middle button down and move the mouse. The display will pan with the cursor.
Zoom In - Roll the scroll wheel (middle button) forward
Zoom Out - Roll the scroll whell (middle button) backward