return the value of the pixel on the upper-left to the pixel whose coordinate is given, 0 if doesn't exist
(x, y)
| 272 | return 0 |
| 273 | |
| 274 | def upper_left_value(x, y) -> int: |
| 275 | """ |
| 276 | return the value of the pixel on the upper-left to the |
| 277 | pixel whose coordinate is given, 0 if doesn't exist |
| 278 | """ |
| 279 | if x - left_distance < 0 or y == 0: |
| 280 | return 0 |
| 281 | else: |
| 282 | return defiltered_bytes[y - 1][x - left_distance] |
| 283 | |
| 284 | def paeth_decide_which_pixel_to_add(x, y) -> tuple: |
| 285 | """ |
nothing calls this directly
no outgoing calls
no test coverage detected