Q. How do I add text?
A. Move the mouse cursor to the desired location and begin typing. It is not necessary to click the mouse before typing. Make sure the mouse does not move while typing. The text will stick to the foremost image, or if no image is present, to the background. Unix versions can also select the font, font size, and weight. Alternatively, text can be positioned interactively by selecting ``Draw..Label'', or by typing on the background and copying it to the image using the ``copy'' function.
In the Unix version, you can also add labels by selecting some text in a text window with the mouse. Click the middle mouse button to paste it onto an image in the desired location.
Larger amounts of text can be added by opening the text file in the same manner as opening an image. The text file must have the extension ``.txt''.
Q. Sometimes the Dismiss button doesn't work, or the Cancel button must be clicked twice.
A. Dismiss buttons on a dialog box are temporarily inactivated if a `child' dialog box or message box is being displayed. Make sure no message boxes or click boxes are visible. In some cases, the message box may become obscured by some other window.
In some situations, for example, when the program is waiting for the user to draw a line, the Cancel button on a dialog box must be clicked twice before the dialog box is dismissed. This is caused by a peculiarity in Motif.
Q. After converting an image to color, any text or graphics added to the image still appears in shades of gray instead of color; or colors are completely wrong.
A. For 8-bit images, only colors on the current colormap associated with the image can be added. If the image previously was grayscale, the colormap will only contain shades of gray. To add different colors, convert the image to 24 bits per pixel and add the colors. When you convert back to 8, a new optimal colormap will be calculated.
Q. How do I select an irregularly-shaped area (i.e., ``scissors'' command)?
A. Press F3, then click the Cancel button when finished.
Q. When I changed the image depth of a scanned image from 10- or 12-bits to 8 bits/pixel, it turned black.
A. For some images, it is necessary to maximize contrast before changing to a different pixel depth. For example, a 10 bit image has pixel values between 0 to 1024, but it is stored in a 16 bit buffer. The contrast must be expanded to 16 bits, otherwise it will appear black when scaled to 8 bits. This is supposed to be done automatically. Please report the problem.
Q. Why use Motif and not KDE or Gnome?
A. KDE and Gnome are Linux-specific and mutually incompatible (i.e., many distributions only install libraries for one or the other). It is not anticipated that tnimage will be ported to either Gnome or KDE until some level of standardization occurs.
Q. It is a pain selecting the menus all the time.
A. All the menus are tear-off menus. Open the menu and click on the dashed line at the top. The menu then tears off and becomes a column of pushbuttons. Alternatively, use the command editor. Or, you can define your own pushbuttons that will automatically be added to the buttons at the left of the main window that will execute any arbitrary command.
Q. How do I undo an operation?
A. Select ``Process...Restore''. The image will be restored to its state at the time it was last backed up. If the image was never explicitly backed up, it will be restored to its original state - unless the ``Auto-Undo'' option has been turned off.
Q. How do I turn off box- or line-drawing mode?
A. Click anywhere on the top menu bar or pull down any menu. This automatically turns off everything. Alternatively, click on the small rectangle which displays the current mode on the right side of the menu bar. In the Unix version, click on the main ``Cancel'' button in the information area.
Q. Is there an easy way to change the color of text, lines, etc.?
A. Yes, click the left mouse button on the color palette to select the foreground color. Click the right mouse button on the palette to select the background color. This will not change the color of any existing text or lines, only new ones.
Q. How do I make the background color white?
A. Select ``Color..Set background color'' and set the color to the highest value (255 on an 8-bit display). Then select ``Image.. erase background'' to redraw the background in the new color (Note: This will erase everything that was drawn on the background).
Q. When filtering, changing contrast, etc. of color images, why does junk or blackness sometimes briefly appear on the screen?
A. If tnimage is in an 8-bit screen mode, manipulating 16 and 24-bit images temporarily causes the image to be filled with 16 or 24 bit data, which appears as random noise because of the discontinuous colormap. After the operation is finished, the colormap is automatically recalculated, and the image will appear normal again.
Q. How can I combine two or more indexed color images into one image so that they have the same colormap?
A. One way is to start tnimage in a color mode by typing: tnimage -xres 800 -bpp 24 (if using DOS version). If using the Unix version, it is necessary to restart the X server in a true-color mode by typing: startx - -bpp 24 or some similar command. Load both images into the same window, then select ``Create image'' and select a region covering both images, using the mouse. Select ``Change image depth'' to convert the image to 1 byte (8 bits) per pixel. A new 8-bit colormap will be generated to fit both images.
Alternatively, use the ``Colormap...Remap to other colormap'' option to map one image onto another's colormap.
Q. Why is xxx image file format not supported?
A. Some image formats (such as GEM IMG) are not commonly used in image analysis. Others (such as lossless JPEG and LZW-compressed TIFF) are not supported because of patent restrictions. However, LZW-compressed TIFF files are readable.
Q. Is a MVS / VMS / Windows-3.1 / Windows-95 (or 97, 98, 0, 2000, etc.) / CE / CP/M / Macintosh/NeXt/Rhapsody / BeOS / Plan9 version of tnimage being planned?
A. There are no current plans.
Q. Is a SunOs 4.x/OpenWindows version of tnimage available?
A. The program requires Motif and does not compile under OpenWindows. If you have Motif somewhere on your disk, the source code version should compile with no problems.
Q. Will lower-resolution screen modes (such as 640 x 480 x 16 colors) ever be supported?
A. No. Reducing the number of colors to 16 would render any quantitative analysis of the image almost meaningless. Users are advised against using 4-bit images for any scientific work, as many such images that have previously appeared in the literature are now being questioned.
Q. How do I scan an 8-bit color image? In the dialog box, all the selections for color images are at least 24 bits/pixel.
A. HP scanners cannot create 8-bit indexed color images. Scan the image at 24 bits and then select ``Color.. Change image depth'' to change the image to 1 byte (8 bits)/pixel. This will automatically generate an optimal colormap.
Q. Why do controls for red, green, and blue appear when I try to change the contrast on my grayscale image?
A. Some other software incorrectly sets the image identifiers in their image to values which indicate the image is ``color'' even though it appears as a gray scale. Selecting ``Color..Convert to grayscale'' will repair the image.
Q. When I set ``chromakey'' on an image it either turns black or disappears entirely, and cannot be selected by clicking on it with the mouse. Is this a bug?
A. No, if the minimum and maximum chromakey values are too broad, the entire image is transparent. If it becomes invisible, clicking on it will only select the background. Select ``Image..image properties'' and change the minimum and maximum to more reasonable values.
Q. In densitometry, all the areas are coming out as negative numbers. What is wrong?
A. Either the ``background value'' or the ``maximum signal'' is set incorrectly.
Q. Why do you use your own TIFF library? Why not just use libtiff?
A. Although libtiff is great for some types of images, it is not ideal for scientific TIFF files. For instance, with ImageQuant files, you may encounter the following error message:
Warning, invalid TIFF directory; tags are not sorted in ascending order.
iq4-05.gel: Warning, TIFF directory is missing required
"StripByteCounts" field, calculating from imagelength.
iq4-05.gel: Can not handle 16-bit/sample image
See sec. 5.9 for more about libtiff.