Automatic Stave Discovery for Musical Facsimiles

Radu Timofte and Luc Van Gool
Paper ID 678, ACCV 2012

This is the supplementary material with automatic stave discovery, binarization and staff removal results for the algorithms presented in the paper. Always we use 5-groups of staff lines for staves and the parameters from the paper. These are examples meant to address steps and methods described in the paper.
pdf


All the supplementary material in a Zip archive


Original

- the original input image. Note that all the images included were reduced to a lower resolution (the images were captured at >100Megapixels resolution) for reasons of space and to prove that our methods work well in these conditions. The images were cropped in order to do not reveal the origin (keep anonymous). Moreover, no other color/image processing methods were employed to normalize, enhance, adapt the input images.

Staves

- the discovered staves and the segmentation are overlaid over the original image. With green segments are marked the musical staves as segmented. With blue segments are marked the parts that belong to background (not staves). Note that we employ a single pass (iteration) for stave discovery over all the images from this supplementary material. Moreover, at this point the results do not contain accurate staff detection.

Stave content

- the discovered stave segments as corresponding to the original image, with the background suppressed to white.

Binarization

- binary image, result of binarization process. Note that due to the fact that we use a global threshold, there are cases where parts of the scores are lost.

Staff removal

- the clean musical symbols after applying stave discovery, stave segmentation, accurate staff detection, and staff removal steps. No other post-processing is employed

Score 1

a quite clean input image

Original Staves Stave content Binarization Staff removal

Score 2

an interesting case - no musical symbols, just staves

Original Staves Stave content Binarization Staff removal

Score 3

two voices, a middle stave with text, below the 6th stave there is a staffline segment that survives the staff removal process because it is outside the stave -- we use the methods like described in the paper

Original Staves Stave content Binarization Staff removal

Score 4

big illustration, interruption with lyrics, strong shadows, small stave segment. While picked by the detection step, the stave going through lyrics is labeled correctly as non-stave / background

Original Staves Stave content Binarization Staff removal

Score 5

Original Staves Stave content Binarization Staff removal

Score 6

a dense score, the last 2 staves are with different spacing than the first 9 staves. The method picks the last stave, but labels it as background since do not fit the expected model built for the first 9 staves. To get staves with different staffline thicknesses and spacings a solution is to repeat the stave discovery process after masking the previously detected and labeled staves.

Original Staves Stave content Binarization Staff removal

Score 7

nice illustrations, two voices, shaded areas where the global threshold fails to clearly separate musical content from background

Original Staves Stave content Binarization Staff removal

Score 8

Original Staves Stave content Binarization Staff removal

Score 9

due to the fact that (here) we cut according to the stave segment, we loose musical symbols that are next to the staves

Original Staves Stave content Binarization Staff removal

Score 10

due to the fact that we cut according to the stave segment, we might loose musical symbols that are next to the staves

Original Staves Stave content Binarization Staff removal

Score 11

a dense score, the last stave is not correctly segmented (with multiple iterations for stave discovery, this would not happen), due to strong shadows and use of global threshold the end of some staves are missed

Original Staves Stave content Binarization Staff removal

Score 12

we run 5-groups of stafflines over 4-groups of stafflines scores and surprisingly the results are quite good, despite wrongfully labeling some stave segments (upper right corner)

Original Staves Stave content Binarization Staff removal

Score 13

with a 5-groups of stafflines system over 4-groups of stafflines scores and very good results

Original Staves Stave content Binarization Staff removal

Score 14

an interesting case - back-shadows automatically picked by the system. The first stave was too saturated wrt the others and got rejected by the stave discovery process. However, in applications the user can limit the values range from where the automatic procedure picks the threshold, thus this case to do not happen.

Original Staves Stave content Binarization Staff removal

Score 15

three voices

Original Staves Stave content Binarization Staff removal

Score 16

Original Staves Stave content Binarization Staff removal

Score 17

back shadows brought to surface (middle left and top left corner), staff removal fails in removing the short middle stave from the right side

Original Staves Stave content Binarization Staff removal

Score 18

three voices

Original Staves Stave content Binarization Staff removal

Score 19

three voices, two short staves are not detected after the one pass/iteration of the automatic stave discovery procedure. After the second iteration, these are properly detected.

Original Staves Stave content Binarization Staff removal

Score 20

small background segment in middle of a stave

Original Staves Stave content Binarization Staff removal

Score 21

symbols out or at the end of the staves that are missed. the cropping follows the stave segments

Original Staves Stave content Binarization Staff removal

Score 22

large illustrations, good results

Original Staves Stave content Binarization Staff removal

Score 23

dense score with symbols out or at the end of the staves that are missed. the cropping follows the stave segments

Original Staves Stave content Binarization Staff removal

Score 24

dense score with symbols out or at the end of the staves that are missed. the cropping follows the stave segments

Original Staves Stave content Binarization Staff removal

Score 25

good results, however the symbols are strongly darkened

Original Staves Stave content Binarization Staff removal

Score 26

good results

Original Staves Stave content Binarization Staff removal

Score 27

good results

Original Staves Stave content Binarization Staff removal


Latest change 13:45 PM 2012/10/04