Image / Bitmap Scale
Posted: Mon Jun 27, 2016 10:47 am
What is a Bitmap?
Bitmaps are images represented by small square-shaped dots called "pixels". For example a bitmap with a size of 800x600 pixels consists of 800x600 small squares with different colors. The size of such a square or pixel is not universally defined and depends on what device the bitmap is displayed and how it is scaled up or down.
When inserting a bitmap into a CAD system (for example for tracing or vectorization), the scale (and often also the angle) of the bitmap have to be adjusted accordingly. There are several ways to achieve this in QCAD.
Defining the Size while Inserting the Bitmap
You can set the desired width or height of the inserted bitmap while inserting the image in the options tool bar at the top: See also reference manual for Draw > Insert Bitmap.
Scaling a Bitmap
After inserting a bitmap, you can scale it just like any other entity using Modify > Scale.
Adjusting the Bitmap Size in the Property Editor
You can also set the image width or height in the property editor (View > Property Editor): Aligning a Bitmap
If you know the size of at least one particular feature in your bitmap or a distance in your bitmap, you can align (rotate and scale) your bitmap using Modify > Align Reference Points.
Situation after inserting the bitmap and click points for the align reference points tool: Result:
Bitmaps are images represented by small square-shaped dots called "pixels". For example a bitmap with a size of 800x600 pixels consists of 800x600 small squares with different colors. The size of such a square or pixel is not universally defined and depends on what device the bitmap is displayed and how it is scaled up or down.
When inserting a bitmap into a CAD system (for example for tracing or vectorization), the scale (and often also the angle) of the bitmap have to be adjusted accordingly. There are several ways to achieve this in QCAD.
Defining the Size while Inserting the Bitmap
You can set the desired width or height of the inserted bitmap while inserting the image in the options tool bar at the top: See also reference manual for Draw > Insert Bitmap.
Scaling a Bitmap
After inserting a bitmap, you can scale it just like any other entity using Modify > Scale.
Adjusting the Bitmap Size in the Property Editor
You can also set the image width or height in the property editor (View > Property Editor): Aligning a Bitmap
If you know the size of at least one particular feature in your bitmap or a distance in your bitmap, you can align (rotate and scale) your bitmap using Modify > Align Reference Points.
Situation after inserting the bitmap and click points for the align reference points tool: Result: