Pictomaphone

The best photo editing app for Windows Phone 7 - back in 2012. All of the original source code is now available for reference.

Pictomaphone was first released on November 5th, 2011 as a free app on the Windows Phone marketplace where it quickly rose to be one of the top free photo editing applications.

In early 2012 I converted it to a paid app with an unlimited free trial (with nag screen) - and in no time it was the top "paid" photo app in the marketplace with over 100,000 users.

Main UX

Background

Windows Phone 7 had some tough limitations that made creating a photo editor difficult.

• The image size for applications was capped at 3 megapixels, even though the phones took higher resolution images.
• Apps ran on Silverlight, which was not very optimized for ARM chips and had its own limitations
• There wasn't a way to call ARM intrinsics for vectorization of math operations
• There wasn't a way to run custom shaders on the GPU
• You couldn't run unsafe code or use pointers

If I were writing a photo editing app in .NET now, I would have so many more options to optimize the code. However, I was able to get the code to a pretty good performance level for those old phones.

• The UI shows a much smaller image for the preview while making adjustments so that it can update "live" - then when OK is chosen it applies the changes to the full image.
• The divide operation was very slow compared to multiply, so wherever possible multiplication is used.
• Lookup tables are created for some operations where it made sense, like curves, to speed up computation time.
• Unrolling operations wherever possible

Photo Editing Features

Pictomaphone had a wide variety of photo adjustments, filters, and effects available.

Edit

• Crop (image)
• Resize
• Rotate / Flip
• Revert

Adjustments

• Brightness and Contrast
• RGB Channel mixer
• Channel overlay
• Color Balance (image 1)
• Color Overlay
• Colorize
• Curves
• Grayscale
• Hue, Saturation, and Lightness
• Levels (image 2)
• Negative
• Posterize
• Sepia
• Solarize
• Temperature and Tone (using LAB colorspace)
• Vibrance (using LAB colorspace)

Effects

• BoxBlur
• Dreamy Glow (a stack blur applied based on brightness)
• Frosted Glass
• Gaussian Blur
• Red Eye fix
• Stack Blur
• Tilt Shift
• Vignette

Filters

Some of the filters are sort-of based on Instagram filters, and others were just ones I liked.

• Brawny (image 1)
• Country
• Cross Process (image 2)
• Lomo
• Old New York
• Summer Forest
• Sunday Morning
• Velvian

Borders

• Square Border