# Image / Bitmap Scale

**URL:** http://forum.qcad.org/t/image-bitmap-scale/2771
**Category:** QCAD Tips and Tutorials
**Created:** [June 27, 2016, 9:47am UTC](http://forum.qcad.org/t/image-bitmap-scale/2771 "2016-06-27T09:47:17Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![andrew](http://forum.qcad.org/user_avatar/forum.qcad.org/andrew/32/7_2.png) [@andrew](http://forum.qcad.org/u/andrew)
#### Post date: [June 27, 2016, 9:47am UTC](http://forum.qcad.org/t/image-bitmap-scale/2771/1 "2016-06-27T09:47:17Z")

</div>

**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:  
 ![Screen Shot 2016-06-27 at 11.44.24.png](https://cdn.qcad.org/original/2X/6/6bcd0dcefeda5f66acde71b6c14a2fec2a0467d8.png)  
See also reference manual for [Draw \> Insert Bitmap](http://qcad.org/doc/qcad/latest/reference/en/index.php?page=scripts/Draw/Image/doc/Image).

**Scaling a Bitmap**

After inserting a bitmap, you can scale it just like any other entity using [Modify \> Scale](http://qcad.org/doc/qcad/latest/reference/en/index.php?page=scripts/Modify/Scale/doc/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):

 ![Screen Shot 2016-06-27 at 11.46.22.png](https://cdn.qcad.org/original/2X/5/513697bb05fabef06d4323281ab008287facd023.png)  
**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](http://qcad.org/doc/qcad/latest/reference/en/index.php?page=scripts/Pro/Modify/AlignReferencePoints/doc/AlignReferencePoints).

Situation after inserting the bitmap and click points for the align reference points tool:

 ![Screen Shot 2016-11-22 at 13.58.01.png](https://cdn.qcad.org/original/2X/d/d99d539121a69d4c0548c789e2fc827b4cf39af9.png)  
Result:  
 ![Screen Shot 2016-11-22 at 13.58.58.png](https://cdn.qcad.org/original/2X/3/3227243c66bd2cdabbd082ea0cf10e1ed8b52c1d.png)