PhotoScore3 Professional and SharpEye v2 Bake-off

On November 19th, 2004 SharpEye2 demo version 2.60 (15 Nov 2004) and PhotoScore3 Professional Demo 3.10 (5 December 2003) were fed two samples of music and the accuracy and features were compared in the task of scanning music for the very specific purpose of individual practice with MIDI accompaniment.

The first music selection was the first page of the guitar part to the song Hora Fetalor. The music consists of complex chords (chord made from notes of different timing with some notes tied or slurred into or out of the chord) and single notes from 8th note triplets to dotted half notes, slurs, dynamics, accents, articulations, and treble clef indicating the notes should be played an octave lower than scored. The fingering is indicated with numbers on nearly every note, but this information is not needed for the computer to play the notes. There are 36 measures on the page with 208 features necessary to accurately play the music as scored.

PhotoScore was fed a 300dpi single-bit black/white .bmp image, which the program warned was sub-optimal. The file size was 857 Kb, scanned on an UMAX Astra 2200 with auto exposure, no scaling, and no filtering. PhotoScore reported 9 rhythm warnings and required 23 corrections. Most errors could be corrected fairly easily, although it was not evident how to fix two complex chord errors, so the wrong notes were deleted. It may be that the two-voice per staff limitation was involved. The scan editor does not add measure numbers, which would have been useful in the editing process. Errors span missed single and chorded notes, extra notes, wrong note values, missing dots, missing slurs and ties, missing sharps, missing naturals, sharps read as notes or naturals, naturals read as sharps, and the octave lowered clef symbol sometimes read as flatted half notes.

SharpEye2 was fed the same 300dpi single-bit black/white image, which is the stated optimal format for the program. SharpEye reported 2 rhythm errors and required three errors to be repaired. The errors were one missing single quarter note, and two missing half notes of a chord.

The second music selection was the first sixteen measures of three staves of Chaminade Scarf Dance scored for flute and piano. The file size was 910 KB, scanned as before. The music consists of complex chords and single 8th notes and rests to dotted half notes, slurs, dynamics, accents, articulations, and a final double bar line with repeat. There is one flat in parentheses as a guide to the performer, which should be ignored by the computer. There are three staves, 16 measures, and 328 features required for the computer to accurately play the scored section.

PhotoScore was fed a slightly skewed 300dpi single-bit black/white .bmp image, which again the program warned was sub-optimal. The program reported 15 rhythm warnings, and made 34 errors. The on screen result was very pretty resulting from accurately reading the title, author, and instrument names and sizing the text. Since the demo has the MIDI file output feature disabled, it was not possible to see if these items would be written to the midi file. The program does allow manually setting the instrument for each staff.

SharpEye2 was fed the same image and reported 6 rhythm warnings and required 12 errors to be corrected. Due to the use of up to four voices in a staff, the program had less trouble interpreting the complex chords.

The second music selection was rescanned at 256 gray-scale and fed to PhotoScore3 Pro demo to see if indeed the program would make fewer errors. The image file size bloomed to over 7mb. The program reported 6 rhythm warnings and still required 27 errors to be corrected.

Bit Total Scan Important Error

Program Image Depth Staves Measures Errors Features Rate

====== ==== === === ======= === ===== =====

PS 1 1 1 36 23 208 11%

SE 1 1 1 36 3 208 1.4%

PS 2 1 3 16 34 328 10%

SE 2 1 3 16 12 328 3.6%

PS 2 256 3 16 27 328 8.2%

The SharpEye2 editor is much more capable, but less intuitive than PhotoScore. Both editors are moded, (different *class* of actions assigned to mouse clicks depending on situation or prior action). There is a very helpful window at the bottom of the SharpEye2 screen with a reminder of what action the left and right mouse will do, but not how to move from one mode or palette to another. The PhotoScore3 Pro demo palette lacked an "invert stem" button, so sometimes it was not evident how to get the edited notes to look exactly like the original...not a concern really for MIDI file production.

Clearing rhythm errors was more difficult in PhotoScore due to the two-voice limitation. There was one three voice rhythm error which could not be cleared in either editor - in PhotoScore3 it would have required three voices, in SharpEye it would have required a way to tell the program which notes belong to which voice. SharpEye did a much better job of assigning its up-to-four voices in complex chords so that the rhythms were most often understood. It was nice not to have to mess with assigning notes to voices in the edit process, where PhotoScore often required editing not just the error but reassigning voice for every note in a measure.

From this "insufficient to make generalizations" sample size of two, the author is expecting SharpEye2 will be two to seven times better at producing usable MIDI files for his flute practice.

Websites:

PhotoScore3 (Neuratron) http://www.neuratron.com/photoscore.htm

SharpEye2 (Visiv) http://www.visiv.co.uk/

Music Selections:

Hora Fetalor, “World Music for Flute & Guitar”, Allan Alexander & Jessica Walsh,

ADG Productions, 2000 http://www.adgproductions.com