Thumbnail PNGs are in b&w not color


Minor problem. I did a search but didnt find the answer. I have PNGs of graphs with maybe 5% coverage, such as a line with red dots (enclosed). Typicalyl 20-50 KByte image mostly white, some black, and a tiny bit of color. OPUS thumbnails + doubleclick display render this in b&W. When I look at digital photographs in OPUS they are rendered perfectly in color.

The thumbnail option "Gray, somewhat faster . . ." is off, and turning it on and then off had no effect.

I'm sending an example chart. Has red dots but looks b&w to Opus 9. Red dots on ACDSEE.

I have V9.0.0.9 SEPT 2007 (32.8 KB)

This seems to happen if the image gets scaled. If you double-click it and view it at 100% size then it doesn't happen.

Because of that I suspect the problem is caused by the special greyscale scaling algorithm in Opus. Opus seems to be incorrectly detecting these images as greyscale and then applying the algorithm to them.

I've sent the image to GPSoft so they can look at it.

Thank you for the quick response. If it's a bug it is a small one.


PS User support for OPUS is really good. I've submitted several Q's and got quick and accurate responses each time.


I have the same problem. Have Dopus Version running under Windows XP Home SP2.

When JPG's are in a base folder, which also contains file, thumnails of jpg's appear in B&W; when I create a subfolder, and move the same jpg's into the subfolder, the same thumbnails are in color.

Any idea of what config changes I can tweak to avoid this B&W display issue? Nella

That sounds rather strange. What is a file? Could you provide a small example zip file which reproduces the problem?


This is to confirm that the thumbnail option "Gray, somewhat faster . . ." is off, and turning it on and then off has no effect.

The file is explained below, per Canon's technical support. I deleted the file and still had the same problem, so I do not think this file's existence explains my problem. I think you correctly identified the issue, when you initially responded to Lamberew's initial post, starting this thread. My testing and workaround, are described below.

First, the background of my situation:

The problem folder in question (call it the root JPG folder, for the sake of identification) has JPG's as well as subfolders containing JPG's. My Dopus Preferences for Lister Display Modes/Thumbnails Mode does not have "generate JPEG thumbnails in gray-scale (slightly faster)" checked. However the preferences "Display thumbnails for folders" AND "Generate folder thumbnails from images inside folder" are checked, as is "Load all thumbnails in a folder automatically."

If I have "High quality image scaling (may be slower)" checked when the the JPG's are "added to this folder", the thumbnails appear in black and white. If I then, in Dopus's preferences, uncheck the "High quality image scaling (may be slower)" box, the B&W thumbnails promptly turn to color. If I then "check" the "High quality image scaling (may be slower)" box, the thumbnails STAY in color, rather than revert to B&W.

I think you correctly identified the issue, when you initially responded to lamberew's initial post, starting this thread. As you said in your response, when I double click on a B&W thumbnail, the image appears in color.

At this point, I don't think it's necessary to send a file as it appears that I'm dealing with the same issue as Lamberew encountered, which you have processed. It would appear that the simple "workaround", for now, is just to make sure the checkbox for "High Quality image scaling" is not checked in Dopus's Preferences/Thumbnails Mode.

Thank you for your thoughts on this issue. Nella

*Canon's ZoomBrowser EX software creates the files. The has information pertaining to the various thumbnail images that represent the images that are contained in your Pictures folder. Nothing will happen if the thumbnail file is deleted. A new one will be created the next time ZoomBrowser EX is launched. It is not necessary to move the thumbnail file when moving images. ZoomBrowser EX will update the thumbnail files as needed.

ZoomBrowser Image Index File
Category Raster Image Files
Common? No
File Description Stores information about images saved in a Zoom Browser photo album; includes thumbnail image data, which enables quick browsing of images in the album; created when one or more image files are opened by ZoomBrowser.

The ZoomBrowser index file is typically named "" and is saved in the same directory as the images it corresponds to; the file is usually hidden, but may appear inside your album folder depending on your computer's file viewing settings.
Program(s) that open info files: Canon ZoomBrowser EX