Measuring, counting and notes in Paint by Zaweba
The Info panel, Ruler, Count and Note tools and the analysis commands in Paint by Zaweba help you measure, straighten, count and record in pictures.
Pictures are not only for looking at. Scientists measure cells in microscope images, surveyors check angles in site photos, retouchers check that a white is really neutral, and anyone straightening a crooked horizon needs to know the angle. Paint by Zaweba has a set of tools for this kind of work: the Info panel, the Ruler tool, the Count tool, the Note tool and the analysis commands under Image > Analysis.
The Info panel
The Info panel shows what is under the pointer. It reads the colour as RGB, HSB, Lab and CMYK, the position in your ruler units, the size of the current selection, the readings of your colour samplers and the ruler's last measurement.
Two extra readings help with print and colour work. Total ink adds up the CMYK percentages, which matters because printers set a limit on how much ink paper can take. Delta E between samplers measures how different two colours look. A small Delta E means the difference is hard to see; a large one means it is obvious. It is the standard way to check whether a colour match is close enough.
The Ruler tool
The Ruler tool measures distance and angle. Drag from one point to another and the Info panel shows the length and the angle of the line. Hold Alt and drag a second line from the end to turn it into a protractor that measures the angle between the two lines, useful for checking angles in architecture or product photos.
It can also straighten a layer. Draw the ruler along something that should be level, such as a horizon or a shelf, then use the straighten option and the layer rotates so that line becomes level. It is the most accurate way to fix a tilted photo.
Next to the ruler sits the Count tool, which places numbered markers as you click. Use it to count birds in a flock, people in a crowd, cells on a slide or items on a pallet. Because each click is numbered, you can see what you have already counted and avoid counting anything twice.
The Note tool
The Note tool pins a text note to a spot in the document. Use notes for instructions to a colleague, reminders of what still needs doing, or comments for a client review. Notes are never exported, so they cannot slip into a finished JPEG or a print file.
Measurements in real units
Image > Analysis turns pixel measurements into real ones. Set Measurement Scale tells Paint how many pixels equal a known length, for example by measuring a scale bar on a microscope image or a ruler laid next to an object in a photo. From then on, measurements read in those units.
Record Measurements writes the current measurement to a log panel, building up a table as you work. When you are done, export the log as CSV and open it in a spreadsheet for averages, charts or a report.
Accurate measurement
Photograph flat objects straight on, with a reference of known size in the same plane. Measurements on a tilted surface will be wrong whatever the software does.
Zoom in when placing ruler ends. A few pixels' error is small on a big object and large on a tiny one.
Set the scale for each new set of images, especially if the zoom or distance changed between shots.
Mistakes to avoid with measurement
Forgetting to set the scale and recording pixel measurements by mistake is common; glance at the units before recording. Using single-pixel colour readings to judge Delta E on noisy photos can mislead; use samplers on smooth areas.
These tools make Paint by Zaweba useful well beyond editing, as a careful measuring and annotating tool for everyday technical work.
