TECHNOLOGY | Slowing down faster-than-time demons

This post provides a Python-fu (GIMP) script that adds nine tween frames between each frame of video decoded as a PNG sequence; it is suited specifically for video shot in the dark, and for video that captured demons moving faster than normal time (i.e., demons that are only seen in one or two still frames due to their speed of movement).

The following still frames demonstrate its effectiveness. The first is a sample of the actual output tween; for comparison, an original, unaltered still frame is also shown:

One of nine tween frames, produced by the script below, that will be placed between two consecutive original still frames to smooth the transition between them 

An original, unaltered still frame, prior to tweening and brightening by the script

If you'd like to process your own videos with this script, and you are unsure how to use GIMP and/or ffmpeg, contact me for help:

#!/usr/bin/env python import gimpfu #access constants from gimpfu import * from os import listdir from os.path import isfile, join def exorcise(*args): mypaths = [args[0]] for mypath in mypaths: included_extensions = ['jpg','bmp','png','gif' ] ; images = [fn for fn in listdir(mypath) if any([fn.endswith(ext) for ext in included_extensions])]; layers = [fn for fn in listdir(mypath) if any([fn.endswith(ext) for ext in included_extensions])]; del layers[0] for i, j in zip(images, layers): try: if i.lower().split(".")[-1] in ("png", "jpg"): if j.lower().split(".")[-1] in ("png", "jpg"): image = pdb.file_png_load(mypath + i, mypath + i) # pdb.gimp_display_new(image) drawable = pdb.gimp_image_get_active_drawable(image) frame1 = pdb.gimp_layer_new_from_drawable(image.layers[0], image) frame2 = pdb.gimp_file_load_layer(image, mypath + j) pdb.gimp_image_add_layer(image, frame1, 0) pdb.gimp_image_add_layer(image, frame2, 0) pdb.gimp_image_rotate(image, 1) pdb.gimp_image_raise_item_to_top(image, frame1) brighten(image, frame1) frame1_bright = pdb.gimp_image_merge_down(image, image.layers[2], 0) frame1_file = pdb.gimp_image_get_filename(image) pdb.file_png_save_defaults(image, frame1_bright, frame1_file, frame1_file) for k in range(1,10): pdb.gimp_image_raise_item_to_top(image, frame2) opacity = k * 10 pdb.gimp_layer_set_opacity(frame2, opacity) tween = pdb.gimp_layer_new_from_visible(image, image, "tween " + str(k)) pdb.gimp_image_add_layer(image, tween, 0) brighten(image, tween) tween_bright = pdb.gimp_image_merge_down(image, image.layers[2], 0) tween_file = pdb.gimp_image_get_filename(image).lower().split(".")[-2] + "a" + str(k) + ".png" pdb.file_png_save_defaults(image, tween_bright, tween_file, tween_file) pdb.gimp_layer_set_visible(tween_bright, 0) pdb.gimp_image_delete(image) except Exception, error: print error break return def brighten(image, src_layer): layer = pdb.gimp_layer_new_from_drawable(src_layer, image) pdb.gimp_image_add_layer(image, layer, 0) fill = pdb.gimp_layer_new(image, pdb.gimp_image_width(image), pdb.gimp_image_height(image), 0, "fill", 100, 5) pdb.gimp_image_add_layer(image, fill, 0) gimp.set_foreground((255, 255, 255)) pdb.gimp_drawable_fill(fill, 0) pdb.gimp_layer_set_mode(fill, VALUE_MODE) value_layer = pdb.gimp_layer_new_from_visible(image, image, "value layer") pdb.gimp_image_add_layer(image, value_layer, 0) pdb.gimp_desaturate_full(value_layer, 1) channel_mask = pdb.gimp_channel_new_from_component(image, 1, "value mask") pdb.gimp_image_add_channel(image, channel_mask, 0) pdb.gimp_layer_set_visible(fill, 0) pdb.gimp_layer_set_visible(value_layer, 0) pdb.gimp_selection_load(channel_mask) layer_mask = pdb.gimp_layer_create_mask(layer, 4) pdb.gimp_layer_add_mask(layer, layer_mask) pdb.gimp_selection_none(image) # pdb.gimp_curves_spline(tween, 0, 6, [0, 0, 127, 255, 255, 0]) pdb.plug_in_colortoalpha(image, layer, (0, 0, 0)) return exorcise("/Users/jamesalanbush/Desktop/testvids/01282014-4test/")