def save(path, image, jpg_quality=None, png_compression=None):
'''
persist :image: object to disk. if path is given, load() first.
jpg_quality: for jpeg only. 0 - 100 (higher means better). Default is 95.
png_compression: For png only. 0 - 9 (higher means a smaller size and longer compression time).
Default is 3.
'''
if isinstance(image, str):
image = load(str)
if jpg_quality:
cv.imwrite(path, image, [cv.IMWRITE_JPEG_QUALITY, jpg_quality])
elif png_compression:
cv.imwrite(path, image, [cv.IMWRITE_PNG_COMPRESSION, png_compression])
else:
cv.imwrite(path, image)
python类IMWRITE_PNG_COMPRESSION的实例源码
def gen_cropped_image(im, rx, cx, size, images, nameString, imageDir,
imgMetaNew, outputImageDir):
imgMetaNew['orig'] = imgMetaNew.filename
imgMetaNew.filename = imgMetaNew.filename.replace(
".png", "_" + nameString + ".png")
croppedImage = cv2.resize(im[rx[0]:rx[1], cx[0]:cx[1], :], (size, size))
params = list()
params.append(cv2.IMWRITE_PNG_COMPRESSION)
params.append(0)
cv2.imwrite(outputImageDir + '/' +
imgMetaNew.filename, croppedImage, params)
images = images.append(imgMetaNew)
return images
def crop_save(image):
crop_image = image[112 + 2:112 + FRAME_SIZE - 2, 192 + 2:192 + FRAME_SIZE - 2]
timestamp = str(time.time())
cv2.imwrite(
'C:\\Users\Akira.DESKTOP-HM7OVCC\Desktop\database\\' + timestamp + '.png',
crop_image,
(cv2.IMWRITE_PNG_COMPRESSION, 0)
)
def from_msg(cls, msg):
"""Serializes a ROS Image message into a compressed PNG image.
Args:
msg: ROS Image or CompressedImage message.
Returns:
Compressed PNG image.
Raises:
CvBridgeError: On image conversion error.
"""
if isinstance(msg, CompressedImage):
# Decompress message.
msg = cls.from_raw(msg.data)
# Convert ROS Image to OpenCV image.
bridge = CvBridge()
img = bridge.imgmsg_to_cv2(msg)
# Convert to PNG with highest level of compression to limit bandwidth
# usage. PNG is used since it is a lossless format, so this can later
# be retrieved as a ROS image without issue.
compression = [cv2.IMWRITE_PNG_COMPRESSION, 9]
png = cv2.imencode(".png", img, compression)[1].tostring()
return png
def pack_img(header, img, quality=80, img_fmt='.jpg'):
"""pack an image into MXImageRecord
Parameters
----------
header : IRHeader
header of the image record
img : numpy.ndarray
image to pack
quality : int
quality for JPEG encoding. 1-100, or compression for PNG encoding. 1-9.
img_fmt : str
Encoding of the image. .jpg for JPEG, .png for PNG.
Returns
-------
s : str
The packed string
"""
assert opencv_available
jpg_formats = set(['.jpg', '.jpeg', '.JPG', '.JPEG'])
png_formats = set(['.png', '.PNG'])
encode_params = None
if img_fmt in jpg_formats:
encode_params = [cv2.IMWRITE_JPEG_QUALITY, quality]
elif img_fmt in png_formats:
encode_params = [cv2.IMWRITE_PNG_COMPRESSION, quality]
ret, buf = cv2.imencode(img_fmt, img, encode_params)
assert ret, 'failed encoding image'
return pack(header, buf.tostring())
def pack_img(header, img, quality=95, img_fmt='.jpg'):
"""pack an image into MXImageRecord
Parameters
----------
header : IRHeader
header of the image record
header.label can be a number or an array.
img : numpy.ndarray
image to pack
quality : int
quality for JPEG encoding. 1-100, or compression for PNG encoding. 1-9.
img_fmt : str
Encoding of the image. .jpg for JPEG, .png for PNG.
Returns
-------
s : str
The packed string
"""
assert opencv_available
jpg_formats = ['.JPG', '.JPEG']
png_formats = ['.PNG']
encode_params = None
if img_fmt.upper() in jpg_formats:
encode_params = [cv2.IMWRITE_JPEG_QUALITY, quality]
elif img_fmt.upper() in png_formats:
encode_params = [cv2.IMWRITE_PNG_COMPRESSION, quality]
ret, buf = cv2.imencode(img_fmt, img, encode_params)
assert ret, 'failed encoding image'
return pack(header, buf.tostring())
def videoSlice(video_path, save_path, progressbarsetter=None, save_type="png", img_comp=0, start_idx=1):
"""
:param video_path:
:param save_path:
:param save_type:
:param img_comp: default0:
None Higher number increase compressive level
png[0-9], jpg[0-100]
:return:
"""
# For read Chinease-name video
vid_handle = cv2.VideoCapture(video_path)
# vid_handle = cv2.VideoCapture(video_path.encode('utf-8'))
fps = vid_handle.get(cv2.CAP_PROP_FPS)
count = vid_handle.get(cv2.CAP_PROP_FRAME_COUNT)
size = (int(vid_handle.get(cv2.CAP_PROP_FRAME_WIDTH)),
int(vid_handle.get(cv2.CAP_PROP_FRAME_HEIGHT)))
prefix = os.path.basename(save_path)
idx = start_idx # start from 000001.xxx
cnt_idx = 1
params = None
suffix = None
if save_type.upper() == "JPEG" or save_type.upper() == "JPG":
img_type = int(cv2.IMWRITE_JPEG_OPTIMIZE)
suffix = ".jpg"
params = [img_type, img_comp]
elif save_type.upper() == "PNG":
img_type = int(cv2.IMWRITE_PNG_COMPRESSION)
suffix = ".png"
params = [img_type, img_comp]
else:
print("Do not support %s format!" % save_type)
while True:
ret, frame = vid_handle.read()
if ret:
cur_progress = cnt_idx/(count/100.0)
if progressbarsetter is not None:
progressbarsetter(cur_progress)
print("Progress %.2f%%" % cur_progress)
img_name = save_path + "/" + ("%06d" % idx) + suffix
# print img_name
print params
cv2.imwrite(img_name, frame, params)
idx += 1
cnt_idx += 1
else:
break
print("Slicing Done!")
return count
