ImageMeter lets you annotate dimensions in your images with ease. No more need to draw a sketch of your new appartment in order to plan the new furniture. Simply take a photo and annotate it with the dimensions on your phone or pad.
What is special about ImageMeter is that it enables you to measure within the image long after you took the picture. It often happens that after taking the picture, being back at home or in the office, one realizes that some important distances have not been measured. This is no problem anymore with ImageMeter, because it enables you to measure the missing data directly from the images, afterwards. Additionally, with this feature, you can also easily add dimensions for places which are too difficult to reach. This works whenever the objects you want to measure are within a plane (even if it is only virtual) and if you can provide a reference rectangle for ImageMeter. ImageMeter will take care of all perspective foreshortening and still measure correctly. You can also have as many measurement planes in one image as you like.
Fig.: Annotated image with automatic measurements carried out in two planes (yellow and red).
When you start ImageMeter, you will see the image collection that is available to ImageMeter. You can use the two top buttons to import pictures already stored on the phone or to capture new pictures with the camera.
Pictures you import into ImageMeter are copied into the app's own memory area. Hence, you can delete the original while the picture will remain available inside ImageMeter.
You can also export your annotated images from the image menu. The size of the exported images can be adjusted in the preferences menu. When exporting multiple images at once, the images are sent in a zip file.
With the 'Edit' button, you switch to the annotation editor for the currently selected picture. Here, you can add dimensions, perform measurements, and change the optical appearance of the annotations. The bottom of the screen shows a menu bar with four categories. Each button opens or closes a submenu which contains the actual functionality.
The five menus are:
- add (for adding new measures to the picture)
- color (change active color)
- style (choose between different drawing styles)
- edit (remove elements, attach dimensions to references, ...)
Fig.: The full ImageMeter menu.
Adding a new dimension measure
To draw a new dimension, open the 'add' menu and choose 'dimension'. The 'add' button starts to blink, indicating that ImageMeter is now waiting for you to draw the new dimension. Touch and drag onto the image to add the dimension.
In order to enter the dimension value, press on the '?' at the dimension, which will open a numerical keypad to enter the dimension value. The dimension value can be specified in several different formats. For length measurements, these include metric units, a special imperial mode for measures like 1' 2 3/4" and free text.
The value input is simplified by an auto-completion and validation feature. Keys that would lead to incorrect inputs are disabled (e.g., two decimal dots). If possible the input will be auto-completed while typing. For example, when typing the fractional measure 1/32", the 2 and the "-symbol will be added automatically.
You can specify the default measure format and units in the app settings together with many parameters like the smallest used numerical fraction, or whether imperial measures should be written with 'ft','in' instead of '/".
Changing element attributes
The middle two menus (color, style) are used to change the visual attributes of elements. The menus behave similarly. You can change either the attribute of the selected element (e.g., the element's color), or choose the default value that will be used for newly added elements.
Note that an element has to be selected so that its attribute can be changed. Further note that you cannot change the color of a dimension that is attached to a reference, since an attached dimension will always share the color of the reference in order to indicate that the reference and the attached dimension belong together.
Carrying out automatic measurements
If you want to use the automatic image-based measuring feature, you first have to provide a reference rectangle to ImageMeter so that it can deduce the correct dimension values automatically.
Select 'add'->'reference' and then touch and drag like you would with a new dimension. However, instead of a line, you are now drawing one side of a rectangle. Align the rectangle to an object in the image for which you know the size. You can either move the corners of the rectangle or its edges. Note that the shape of the reference must be a rectangle in the real world, but can be an arbitrary quadrilateral in the image, because of perspective distortions.
Finally, add the known horizontal and vertical dimensions of the rectangle as usual.
Adding dimensions attached to a reference
You can measure any object in the plane of the reference object by adding a dimension object as described above. If a reference object is selected when adding a new dimension, the new dimension will be automatically attached to the reference object.
After you added the new dimension, its value is automatically computed and shown. When you modify the dimension, its value also adapts automatically.
Attaching / detaching dimensions
If you forgot to select a reference while drawing a dimension, you can attach it to the reference later by choosing 'edit'->'attach'.
On the contrary, you can detach a dimension from its reference by choosing 'edit'->'detach'.
Automatic measurements with incomplete data
Sometimes, you will not be able to provide both sizes of the reference rectangle. In this case, ImageMeter will try to get the most out of this situation. Let's say that you only know the size in horizontal direction. and consequently leave the verical size undefined. If you now draw a dimension attached to this reference, ImageMeter will still be able to compute the correct length as long as you are measuring in the horizontal direction. This is indicated with the text "H: ..." in front of the dimension text. If you deviate from this direction, the measurement gets increasingly inaccurate, which is first indicated as "~20.4m" and later as "(21.7m)".
Even when you do not know, e.g., the vertical size, ImageMeter still considers the shape of the reference in order to compute the vanishing point and consider the perspective foreshortening.
Fig.: Automatic measuring when one dimension (vertical) is unknown. You can still measure in horizontal direction.
Area within reference rectangle
As a convenience feature, ImageMeter can compute and display the area of the reference rectangle. To activate this feature, simply select 'show area' in the style menu when a reference is active.
Adding angle measurements is quite similar to adding dimensions. Select 'add'->'angle' from the menu and then touch and drag one side of angle. Afterwards, adjust the angle as desired.
When you attach the angle to a reference, angles are measured automatically in the plance of the reference.
You can also measure arbitrarily shaped areas. After selecting 'add'->'area' from the menu. Touch and drag one side of the area. This will initially generate a new square. You can drag the corners like on a reference rectangle. However, if you drag from a side, a new corner will be inserted into the contour, so that you can draw arbitrarily complex areas. When you move a corner onto the straight line between the two adjacent corners, that part of the contour will be drawn with dashes. If you release the corner in this position, it will be removed and that part of the contour will be replaced with a straight line.
Fig.: (left) adding a new corner to the contour of an area.
(right) removing a corner.
Connecting a Laser Distance Meter via Bluetooth
ImageMeter supports Bluetooth connectivity to the Leica Disto laser distance meters (tested on D3a-BT, D8, and A6). To connect to the distance meter, you have to pair the meter with your Android device. Afterwards, choose the distance meter you want to use in the ImageMeter settings.
To establish the connection, enable Bluetooth on the laser distance meter and then press the Bluetooth button on the ImageMeter home screen. The button will turn yellow, indicating that it is trying to connect to the device. If it succeeds, the button will turn blue, indicating that it is ready to use.
To transmit a measure via Bluetooth, first draw a new measure in ImageMeter or select an existing measure. Simply pressing the Bluetooth button on the laser distance meter now sends the current measurement to ImageMeter.
You can send length measurements, but also angles and areas. Clearly, ImageMeter will only accept measures for the correct annotation element. Note that ImageMeter automatically selects the display format of the measure depending on the settings on your laser distance meter.
The accuracy of the automatic measures depends on the quality of the camera optics of your phone. Some phone cameras may show significant geometric distortions.
In order to maximize accuracy, you should choose a reference that is as large as possible and capture images with a high resolution in order to be able to position the reference and dimensions more exactly.