Line and Arrow Tool

Moderator: jsachs

Post Reply
GregL65
Posts: 10
Joined: October 4th, 2021, 2:21 am

Line and Arrow Tool

Post by GregL65 »

I'm transitioning from 7 to 8. I'm confused about the Line and Arrow tool in 8.

I'm processing scans of children's story illustrations from century-old newspapers for inclusion in ebooks. One part of the workflow is to rotate them to exact horizontal. When these illustrations are zoomed to full screen on a Kindle or other ebook reader device, if they're even a fraction of a degree off it's obvious and unattractive.

Here's what I did in 7:

- Choose my reference for horizontal in the illustrtaion. That reference might be the bottom border of the illustration if there is one, or it might be the longest line of the caption.
- Zoom until my reference for horizontal fills all of the available horizontal space.
- Click the Line and Arrow tool icon.
- Accepting all defaults on the tool, I draw a line from one far side of the horizontal reference to the other far side.
- I look at the tool dialog to see the line's angle. I subtract from 180 (or -180) to get the rotation needed. For example if it says 178.123, I'll make a mental note that the rotation needed is 1.877 (this was a bit easier in 5 as the tool's dialog gave the line's angle as e.g. 1.877).
- I undo the line and dismiss the tool icon.
- I go into Transformaion > Geometry > Crop/Add Border. I do a Reset All to make sure everything is default, then enter the required rotation amount into the Angle edit box, and click OK.
- Finally, I zoom again and move the horizontal reference down to the bottom border of the screen to verify that it's now exactly horizontal (or as much so as possible for these old illustrations).

Here's what I tried in 8:

- I zoomed until the illustration's bottom border filled the available horizontal space. I like how that's a faster step now, and seems to have more zoom increments.
- I chose Transformation > Tool > Lines, Arrows, Text.
- The first thing I notice is that now I have two images views side by side. Both zoomed out to fit to window. The dialog tells me that those two images are input and preview. I guess I want preview, so I click "Display Preview" to dismiss the input image.
- But the preview image is still zoomed to fit window. When I try to zoom in with the mouse wheel, it just changes the line width setting on the tool. I don't see how to zoom in.
- I try to draw a line and nothing happens.
- On the tool I see that it's defaulting to white for the line color. I change it to black and try again. Still no line.
- I see that the new tool has a control for "Create or Edit Amount Mask". Do I need to create a mask to draw a line? I click on it and choose New Mask. In the Mask dialog, I choose "Mask Only" and dismiss the Mask dialog. I notice that now the Amount slider has two sliders, a white one at top at 100%, and a black one on the bottom at 0%.
- I try to draw a line. Nothing happens.
- I slide the black Amount slider from 0% to 100%. Try drawing a line again, still nothing.
- Did I need the Input image rather than the Preview image? I dismiss the dialog and start over, this time dismissing the Preview window to show only the Input window, and try again. Still no line.

So, I have two questions:
- How do I zoom in further than Fit to Window when I want to draw a line?
- How do I draw the line?

Apologies if I've missed something obvious.
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Line and Arrow Tool

Post by jsachs »

You're making it much more complicated than necessary -- just use Transformation/Geometry/Level and drag the overlay line until it lines up with the horizontals in the image.

As a convenience, some transformations use the mouse wheel to control the Radius slider. In those cases, Alt-Scroll Wheel zooms. Or, just use the Zoom In or Zoom Out buttons (magnifier + and -) in the tool bar just above the Input or Preview window. Or use the + and - keys in the numeric keypad.

The procedure for drawing lines is described in the Help file -- just click the ? button in the transformation dialog box. In short, Shift-click on the input image to set one endpoint and then click to add one or more points to the line. New points are added between the nearest two existing points, unless the nearest existing point is an endpoint in which case they are added at the end. Ctrl-click removes control points. Lines can either be made up or straight line segments of spline curves and may or may not have arrowheads at the end. A text box is also option aligned with the starting point of the line.
Jonathan Sachs
Digital Light & Color
GregL65
Posts: 10
Joined: October 4th, 2021, 2:21 am

Re: Line and Arrow Tool

Post by GregL65 »

Thanks, that's what I needed.
Post Reply