#!/usr/bin/env python3
import tempfile
import os.path as path
import os
import sys
import time
import shutil
import math
import gerber
from gerber.render.cairo_backend import GerberCairoContext
import numpy as np
import cv2
import enum
import tqdm
class Unit(enum.Enum):
MM = 0
INCH = 1
MIL = 2
def generate_mask(
outline,
target,
scale,
debugimg,
status_print,
gerber_unit,
extend_overlay_r_mil,
subtract_gerber
):
# Render all gerber layers whose features are to be excluded from the target image, such as board outline, the
# original silk layer and the solder paste layer to binary images.
with tempfile.TemporaryDirectory() as tmpdir:
img_file = path.join(tmpdir, 'target.png')
status_print('Combining keepout composite')
fg, bg = gerber.render.RenderSettings((1, 1, 1)), gerber.render.RenderSettings((0, 0, 0))
ctx = GerberCairoContext(scale=scale)
status_print(' * outline')
ctx.render_layer(outline, settings=fg, bgsettings=bg)
status_print(' * target layer')
ctx.render_layer(target, settings=fg, bgsettings=bg)
for fn, sub in subtract_gerber:
status_print(' * extra layer', os.path.basename(fn))
layer = gerber.loads(sub)
ctx.render_layer(layer, settings=fg, bgsettings=bg)
status_print('Rendering keepout composite')
ctx.dump(img_file)
# Vertically flip exported image
original_img = cv2.imread(img_file, cv2.IMREAD_GRAYSCALE)[::-1, :]
f = 1 if gerber_unit == Unit.INCH else 25.4 # MM
r = 1+2*max(1, int(extend_overlay_r_mil/1000 * f * scale))
status_print('Expanding keepout composite by', r)
# Extend image by a few pixels and flood-fill from (0, 0) to mask out the area outside the outermost outline
# This ensures no polygons are generated outside the board even for non-rectangular boards.
border = 10
outh, outw = original_img.shape
extended_img = np.zeros((outh + 2*border, outw + 2*border), dtype=np.uint8)
extended_img[border:outh+border, border:outw+border] = original_img
cv2.floodFill(extended_img, None, (0, 0), (255,))
original_img = extended_img[border:outh+border, border:outw+border]
debugimg(extended_img, 'flooded')
# Dilate the white areas of the image using gaussian blur and threshold. Use these instead of primitive dilation
# here for their non-directionality.
target_img = cv2.blur(original_img, (r, r))
_, target_img = cv2.threshold(target_img, 255//(1+r), 255, cv2.THRESH_BINARY)
return target_img
def render_gerbers_to_image(*gerbers, scale, bounds=None):
with tempfile.TemporaryDirectory() as tmpdir:
img_file = path.join(tmpdir, 'target.png')
fg, bg = gerber.render.RenderSettings((1, 1, 1)), gerber.render.RenderSettings((0, 0, 0))
ctx = GerberCairoContext(scale=scale)
for grb in gerbers:
ctx.render_layer(grb, settings=fg, bgsettings=bg, bounds=bounds)
ctx.dump(img_file)
# Vertically flip exported image to align coordinate systems
return cv2.imread(img_file, cv2.IMREAD_GRAYSCALE)[::-1, :]
def pcb_area_mask(outline, scale):
# Merge layers to target mask
img = render_gerbers_to_image(outline, scale=scale)
# Extend
imgh, imgw = img.shape
img_ext = np.zeros(shape=(imgh+2, imgw+2), dtype=np.uint8)
img_ext[1:-1, 1:-1] = img
# Binarize
img_ext[img_ext < 128] = 0
img_ext[img_ext >= 128] = 255
# Flood-fill
cv2.floodFill(img_ext, None, (0, 0), (255,)) # Flood-fill with white from top left corner (0,0)
img_ext_snap = img_ext.copy()
cv2.floodFill(img_ext, None, (0, 0), (0,)) # Flood-fill with black
cv2.floodFill(img_ext, None, (0, 0), (255,)) # Flood-fill with white
return np.logical_xor(img_ext_snap, img_ext)[1:-1, 1:-1].astype(float)
def generate_template(
silk, mask, copper, outline, drill,
image,
gerber_unit=Unit.MM,
process_resolution:float=6, # mil
resolution_oversampling:float=10, # times
status_print=lambda *args:None
):
silk, mask, copper, outline, *drill = map(gerber.load_layer_data, [silk, mask, copper, outline, *drill])
silk.layer_class = 'topsilk'
mask.layer_class = 'topmask'
copper.layer_class = 'top'
outline.layer_class = 'outline'
scale = (1000/process_resolution) / 25.4 * resolution_oversampling # dpmm
# Create a new drawing context
ctx = GerberCairoContext(scale=scale)
ctx.render_layer(outline)
ctx.render_layer(copper)
ctx.render_layer(mask)
ctx.render_layer(silk)
for dr in drill:
ctx.render_layer(dr)
ctx.dump(image)
def paste_image(
target_gerber:str,
outline_gerber:str,
source_img:np.ndarray,
subtract_gerber:list=[],
extend_overlay_r_mil:float=6,
extend_picture_r_mil:float=2,
status_print=lambda *args:None,
gerber_unit=Unit.MM,
debugdir:str=None):
debugctr = 0
def debugimg(img, name):
nonlocal debugctr
if debugdir:
cv2.imwrite(path.join(debugdir, '{:02d}{}.png'.format(debugctr, name)), img)
debugctr += 1
# Parse outline layer to get bounds of gerber file
status_print('Parsing outline gerber')
outline = gerber.loads(outline_gerber)
(minx, maxx), (miny, maxy) = outline.bounds
grbw, grbh = maxx - minx, maxy - miny
status_print(' * outline has offset {}, size {}'.format((minx, miny), (grbw, grbh)))
# Parse target layer
status_print('Parsing target gerber')
target = gerber.loads(target_gerber)
(tminx, tmaxx), (tminy, tmaxy) = target.bounds
status_print(' * target layer has offset {}, size {}'.format((tminx, tminy), (tmaxx-tminx, tmaxy-tminy)))
# Read source image
imgh, imgw = source_img.shape
scale = math.ceil(max(imgw/grbw, imgh/grbh)) # scale is in dpmm
status_print(' * source image has size {}, going for scale {}dpmm'.format((imgw, imgh), scale))
# Merge layers to target mask
target_img = generate_mask(outline, target, scale, debugimg, status_print, gerber_unit, extend_overlay_r_mil, subtract_gerber)
# Threshold source image. Ideally, the source image is already binary but in case it's not, or in case it's not
# exactly binary (having a few very dark or very light grays e.g. due to JPEG compression) we're thresholding here.
status_print('Thresholding source image')
qr = 1+2*max(1, int(extend_picture_r_mil/1000 * scale))
source_img = source_img[::-1]
_, source_img = cv2.threshold(source_img, 127, 255, cv2.THRESH_BINARY)
debugimg(source_img, 'thresh')
# Pad image to size of target layer images generated above. After this, `scale` applies to the padded image as well
# as the gerber renders. For padding, zoom or shrink the image to completely fit the gerber's rectangular bounding
# box. Center the image vertically or horizontally if it has a different aspect ratio.
status_print('Padding source image')
tgth, tgtw = target_img.shape
padded_img = np.zeros(shape=target_img.shape, dtype=source_img.dtype)
offx = int((minx-tminx if tminx < minx else 0)*scale)
offy = int((miny-tminy if tminy < miny else 0)*scale)
offx += int(grbw*scale - imgw) // 2
offy += int(grbh*scale - imgh) // 2
endx, endy = min(offx+imgw, tgtw), min(offy+imgh, tgth)
print('off', (offx, offy), 'end', (endx, endy), 'img', (imgw, imgh), 'tgt', (tgtw, tgth))
padded_img[offy:endy, offx:endx] = source_img[:endy-offy, :endx-offx]
debugimg(padded_img, 'padded')
debugimg(target_img, 'target')
# Mask out excluded gerber features (source silk, holes, solder mask etc.) from the target image
status_print('Masking source image')
out_img = (np.multiply((padded_img/255.0), (target_img/255.0) * -1 + 1) * 255).astype(np.uint8)
debugimg(out_img, 'multiplied')
# Calculate contours from masked target image and plot them to the target gerber context
status_print('Calculating contour lines')
plot_contours(out_img,
target,
offx=(minx, miny),
scale=scale,
status_print=lambda *args: status_print(' ', *args))
# Write target gerber context to disk
status_print('Generating output gerber')
from gerber.render import rs274x_backend
ctx = rs274x_backend.Rs274xContext(target.settings)
target.render(ctx)
out = ctx.dump().getvalue()
status_print('Done.')
return out
def plot_contours(
img:np.ndarray,
layer:gerber.rs274x.GerberFile,
offx:tuple,
scale:float,
debug=lambda *args:None,
status_print=lambda *args:None):
from gerber.primitives import Line, Region, Circle
imgh, imgw = img.shape
# Extract contour hierarchy using OpenCV
status_print('Extracting contours')
# See https://stackoverflow.com/questions/48291581/how-to-use-cv2-findcontours-in-different-opencv-versions/48292371
contours, hierarchy = cv2.findContours(img, cv2.RETR_TREE, cv2.CHAIN_APPROX_TC89_KCOS)[-2:]
aperture = list(layer.apertures)[0] if layer.apertures else Circle(None, 0.10)
status_print('offx', offx, 'scale', scale)
xbias, ybias = offx
def map(coord):
x, y = coord
return (x/scale + xbias, y/scale + ybias)
def contour_lines(c):
return [ Line(map(start), map(end), aperture, units=layer.settings.units)
for start, end in zip(c, np.vstack((c[1:], c[:1]))) ]
done = []
process_stack = [-1]
next_process_stack = []
parents = [ (i, first_child != -1, parent) for i, (_1, _2, first_child, parent) in enumerate(hierarchy[0]) ]
is_dark = True
status_print('Converting contours to gerber primitives')
with tqdm.tqdm(total=len(contours)) as progress:
while len(done) != len(contours):
for i, has_children, parent in parents[:]:
if parent in process_stack:
contour = contours[i]
polarity = 'dark' if is_dark else 'clear'
debug('rendering {} with parent {} as {} with {} vertices'.format(i, parent, polarity, len(contour)))
debug('process_stack is', process_stack)
debug()
layer.primitives.append(Region(contour_lines(contour[:,0]), level_polarity=polarity, units=layer.settings.units))
if has_children:
next_process_stack.append(i)
done.append(i)
parents.remove((i, has_children, parent))
progress.update(1)
debug('skipping to next level')
process_stack, next_process_stack = next_process_stack, []
is_dark = not is_dark
debug('done', done)
# Utility foo
# ===========
def find_gerber_in_dir(dir_path, extensions, exclude=''):
contents = os.listdir(dir_path)
exts = extensions.split('|')
excs = exclude.split('|')
for entry in contents:
if any(entry.lower().endswith(ext.lower()) for ext in exts) and not any(entry.lower().endswith(ex) for ex in excs if exclude):
lname = path.join(dir_path, entry)
if not path.isfile(lname):
continue
with open(lname, 'r') as f:
return lname, f.read()
raise ValueError(f'Cannot find file with suffix {extensions} in dir {dir_path}')
# Gerber file name extensions for Altium/Protel | KiCAD | Eagle
LAYER_SPEC = {
'top': {
'paste': '.gtp|-F_Paste.gbr|-F.Paste.gbr|.pmc',
'silk': '.gto|-F_SilkS.gbr|-F.SilkS.gbr|.plc',
'mask': '.gts|-F_Mask.gbr|-F.Mask.gbr|.stc',
'copper': '.gtl|-F_Cu.gbr|-F.Cu.gbr|.cmp',
'outline': '.gko|.gm1|-Edge_Cuts.gbr|-Edge.Cuts.gbr|.gmb',
},
'bottom': {
'paste': '.gbp|-B_Paste.gbr|-B.Paste.gbr|.pms',
'silk': '.gbo|-B_SilkS.gbr|-B.SilkS.gbr|.pls',
'mask': '.gbs|-B_Mask.gbr|-B.Mask.gbr|.sts',
'copper': '.gbl|-B_Cu.gbr|-B.Cu.gbr|.sol',
'outline': '.gko|.gm1|-Edge_Cuts.gbr|-Edge.Cuts.gbr|.gmb'
},
}
# Command line interface
# ======================
def process_gerbers(source, target, image, side, layer, debugdir):
if not os.path.isdir(source):
raise ValueError(f'Given source "{source}" is not a directory.')
# Load input files
source_img = cv2.imread(image, cv2.IMREAD_GRAYSCALE)
if source_img is None:
print(f'"{image}" is not a valid image file', file=sys.stderr)
sys.exit(1)
tlayer, slayer = {
'silk': ('silk', 'mask'),
'mask': ('mask', 'silk'),
'copper': ('copper', None)
}[layer]
layers = LAYER_SPEC[side]
tname, tgrb = find_gerber_in_dir(source, layers[tlayer])
print('Target layer file {}'.format(os.path.basename(tname)))
oname, ogrb = find_gerber_in_dir(source, layers['outline'])
print('Outline layer file {}'.format(os.path.basename(oname)))
subtract = find_gerber_in_dir(source, layers[slayer]) if slayer else None
# Prepare output. Do this now to error out as early as possible if there's a problem.
if os.path.exists(target):
if os.path.isdir(target) and sorted(os.listdir(target)) == sorted(os.listdir(source)):
shutil.rmtree(target)
else:
print('Error: Target already exists and does not look like source. Please manually remove the target dir before proceeding.', file=sys.stderr)
sys.exit(1)
# Generate output
out = paste_image(tgrb, ogrb, source_img, [subtract], debugdir=debugdir, status_print=lambda *args: print(*args, flush=True))
shutil.copytree(source, target)
with open(os.path.join(target, os.path.basename(tname)), 'w') as f:
f.write(out)
def render_preview(source, image, side, process_resolution, resolution_oversampling):
def load_layer(layer):
name, grb = find_gerber_in_dir(source, LAYER_SPEC[side][layer])
print(f'{layer} layer file {os.path.basename(name)}')
return grb
outline = load_layer('outline')
silk = load_layer('silk')
mask = load_layer('mask')
copper = load_layer('copper')
try:
nm, npth = find_gerber_in_dir(source, '-npth.drl')
print(f'npth drill file {nm}')
except ValueError:
npth = None
nm, drill = find_gerber_in_dir(source, '.drl|.txt', exclude='-npth.drl')
print(f'drill file {nm}')
drill = ([npth] if npth else []) + [drill]
generate_template(
silk, mask, copper, outline, drill,
image,
gerber_unit=Unit.MM,
process_resolution=process_resolution,
resolution_oversampling=resolution_oversampling,
)