Working with Images

What is bit depth in relation to images? What are the most common bit depths in use today?

Bit depth refers to the color information stored in an image. The number of bits equals the number of color values applied to each pixel. The simple 1-bit image can only show 1 of 2 values,  black or white. An 8-bit image can store 256 colors (28), while a 24-bit image can store a whopping 16 million or so (224) colors per pixel. The most common bit depths are 8-24 bits, 8-bit being used primarily in animated .gifs.

Define vector and bitmap and include an example image you created in Acorn that demonstrates your understanding.

A vector image is a smart object that is drawn by the computer each time it is rendered using mathematics. A bitmap image is more like a painting with each pixel permanently fixed in color. A vector drawing will always render a high, smooth resolution, whereas a bitmap will look pixelated when rendered at a higher resolution and lose data when rendered at a lower resolution.

Here is an image I created in Adobe Photoshop using both bitmap tools and vector-based smart objects. I took my photo with my MacBook Pro camera, removed the background using the magic wand tool and eraser. I then created a vector mask on that layer and inserted a rainbow gradient. Finally, I framed the whole enchilada with a smart object rectangle, then applied the bevel and emboss fx to the object. I flattened the layers and saved as a .png. Voila!

What file format constitutes your editable original?​ What file formats are generally shared via the internet?

An editable original in Photoshop is a .psd file. Image files on the web are usually .png, .gif, or .jpg.

​Explain the essential properties of the three most common graphic file formats used on the web.

How can you transfer an image found on the web to your hard drive for use in a classroom presentation?

Control-click on the image, select “Save As…” from the drop-down menu, then select where you want to save it. Make a note of the attributions to give proper credit.

Explain the process of creating a good quality image from notation created in Sibelius or NoteFlight.

Export the file as a .pdf, open it in a .pdf viewer or Photoshop, then crop the image and save as a .png.

Link to at least three resources online that contain image content you might use in your teaching.​

These websites host Public Domain and Creative Commons content that supports educational use.

Metropolitan Museum of Art Initiative
LIFE Photo Archive hosted by Google
New York Public Library Public Domain Collection


Related Fun Facts

Double reeds are cool! Click the image to learn more!

Sea Dragon, 17th c. Italian double reed instrument
The Crosby Brown Collection of Musical Instruments, 1889
The Metropolitan Museum of Art

Music, Technology, Education