Sha256: f53380111932b5102456cfa921583ba6fb98cdf8add516a9793f4014ff072c60
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Versions: 15
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Contents
#!/usr/bin/ruby # An equivalent of ImageMagick's -trim in ruby-vips ... automatically remove # "boring" image edges. # We use .project to sum the rows and columns of a 0/255 mask image, the first # non-zero row or column is the object edge. We make the mask image with an # amount-different-from-background image plus a threshold. require "vips" im = Vips::Image.new_from_file ARGV[0] # find the value of the pixel at (0, 0) ... we will search for all pixels # significantly different from this background = im.getpoint(0, 0) # we need to smooth the image, subtract the background from every pixel, take # the absolute value of the difference, then threshold mask = (im.median - background).abs > 10 # sum mask rows and columns, then search for the first non-zero sum in each # direction columns, rows = mask.project _first_column, first_row = columns.profile left = first_row.min _first_column, first_row = columns.fliphor.profile right = columns.width - first_row.min first_column, _first_row = rows.profile top = first_column.min first_column, _first_row = rows.flipver.profile bottom = rows.height - first_column.min # and now crop the original image im = im.crop left, top, right - left, bottom - top im.write_to_file ARGV[1]
Version data entries
15 entries across 14 versions & 4 rubygems