split-file-to-bitmaps

#!/bin/bash

WIDTH=320
HEIGHT=240

INPUT_FILENAME="nasa-20210604.jpg"
OUTPUT_FILENAME_PREFIX="output_before_"

SLICE=0
OUTPUT_FILENAME="${OUTPUT_FILENAME_PREFIX}${SLICE}.bmp"
./file-to-bmp ${INPUT_FILENAME} ${WIDTH} ${HEIGHT} ${SLICE} ${OUTPUT_FILENAME}
if [ $? -ne 0 ]; then
  echo "Nonzero exit status from the first frame conversion!"
  echo "Attempted command: ./file-to-bmp ${INPUT_FILENAME} ${WIDTH} ${HEIGHT} ${SLICE} ${OUTPUT_FILENAME}"
  echo "Exiting..."
  return 1
fi

while [ $? -eq 0 ]; do
  SLICE=$(expr ${SLICE} + 1)
  OUTPUT_FILENAME="${OUTPUT_FILENAME_PREFIX}${SLICE}.bmp"
  echo ${OUTPUT_FILENAME}
  ./file-to-bmp ${INPUT_FILENAME} ${WIDTH} ${HEIGHT} ${SLICE} ${OUTPUT_FILENAME}
done

NUM_SLICES=${SLICE}

echo "Created ${NUM_SLICES} slices!"

SLICE=0
while [ ${SLICE} -lt ${NUM_SLICES} ]; do
  echo "Processing slice ${SLICE}..."
  OUTPUT_FILENAME_BMP="${OUTPUT_FILENAME_PREFIX}${SLICE}.bmp"
  OUTPUT_FILENAME_PNG="${OUTPUT_FILENAME_PREFIX}${SLICE}.png"
  convert ${OUTPUT_FILENAME_BMP} ${OUTPUT_FILENAME_PNG}
  rm ${OUTPUT_FILENAME_BMP}
  SLICE=$(expr ${SLICE} + 1)
done