I'm looking to write a signature to PDF. I'm using JSignature and Reportlab. My code works successfully for writing the data to a file and the database. I just cannot figure out how to write the signature to the canvas. Has anyone passed the signature into the canvas successfully?
Thank you in advance.
Here's a look at my code:
pdf.py
import io
from django.core.files.base import ContentFile
from reportlab.lib.units import inch
from reportlab.pdfgen import canvas
from reportlab.lib.utils import ImageReader
def create_pdf(parent):
# create a file-like buffer to receive PDF data
buffer = io.BytesIO()
# create the pdf object, using the buffer as its "file"
p = canvas.Canvas(buffer)
# create text
textobject = p.beginText()
# start text at top left of page
textobject.setTextOrigin(inch, 11*inch)
# set font and size
textobject.setFont("Helvetica-Bold", 18)
textobject.textLine("My Document")
textobject.textLine("")
# write page 1
textobject.setFont("Helvetica", 12)
p_name = f'Name: {participant.first_name} {participant.middle_initial} {participant.last_name}'
textobject.textLine(p_name)
sig = f'Signature:'
textobject.textLine(sig)
----insert signature here----
# write created text to canvas
p.drawText(textobject)
# close the pdf canvas
p.showPage()
p.save()
buffer.seek(0)
# get content of buffer
pdf_data = buffer.getvalue()
# save to django File object
file_data = ContentFile(pdf_data)
# name the file
file_data.name = f'{participant.last_name}.pdf'
#
participant.pdf = file_data
participant.save()
Model:
class Participant(models.Model):
first_name = models.CharField(max_length=50)
middle_initial = models.CharField(max_length=50, blank=True)
last_name = models.CharField(max_length=50, blank=True)
signature = JSignatureField()
pdf = models.FileField(blank=True, null=True)
For those interested in how I was able to get this functioning. The primary issue was The image would be completely black when pulling it into the PDF. Here’s what is required:
In your View:
Use the Jsignature draw_signature function and get the image:
rsr_image = draw_signature(signature)
save the signature as a PNG and then store
# save signature as png to prevent darkening, save to model
rsr_file_name = str(new_parent.id)+'_rsr.png'
buffer = BytesIO()
rsr_image.save(buffer, 'PNG')
new_parent.rsr_image.save(rsr_file_name, File(buffer))
Create the following function, in order to…
Open the image, create a new background for the image, and save it.
def get_jpeg_image(new_parent):
# open png image
png_image = Image.open(new_parent.rsr_image)
# create new image with 'RGB' mode which is compatible with jpeg,
# with same size as old and with white(255,255,255) background
bg = Image.new("RGB", png_image.size, (255, 255, 255))
# paste old image pixels in new background
bg.paste(png_image, png_image)
# give image file name
file_name_jpeg = str(new_parent.id)+'.jpg'
bg.save(file_name_jpeg)
return file_name_jpeg
Reference that function inside your create PDF function to convert the PNG to JPG
jpeg_image = get_jpeg_image(participant)
Hope this helps someone.
Related
I want to save each page of a pdf file as a single image file:
import fitz
doc = fitz.open('file.pdf')
for i in range(doc.page_count):
page = doc[i]
pix = page.get_pixmap()
pix.save(f'page-{i}.png')
pix.pil_save(f'page-{i}.jpg', optimize = False, dpi = (1500, 1500))
The images are in worse quality than in the original pdf file, no matter which resolution I choose. How can I save them with the same or a similar quality?
Just a simple configuration, Add the dpi option in get_pixmap()
import fitz
doc = fitz.open('file.pdf')
resolution_parameter = 300
for i in range(doc.page_count):
page = doc[i]
pix = page.get_pixmap(dpi = resolution_parameter)
pix.save(f'page-{i}.png')
pix.pil_save(f'page-{i}.jpg', optimize = False, dpi = (1500, 1500))
i'm writing a program which takes all the pictures in a given folder and aggregates them into a pdf. The problem I have is that when the images are drawn, they are bigger in size and are rotated to the left oddly. I've searched everywhere, havent found anything even in the reportlab documentation.
Here's the code:
import os
from PIL import Image
from PyPDF2 import PdfFileWriter, PdfFileReader
from reportlab.pdfgen import canvas
from reportlab.lib.units import cm
from StringIO import StringIO
def main():
images = image_search()
output = PdfFileWriter()
for image in images:
Image_file = Image.open(image) # need to convert the image to the specific size first.
width, height = Image_file.size
im_width = 1 * cm
# Using ReportLab to insert image into PDF
watermark_str = "watermark" + str(images.index(image)) + '.pdf'
imgDoc = canvas.Canvas(watermark_str)
# Draw image on Canvas and save PDF in buffer
# define the aspect ratio first
aspect = height / float(width)
## Drawing the image
imgDoc.drawImage(image, 0,0, width = im_width, height = (im_width * aspect)) ## at (399,760) with size 160x160
imgDoc.showPage()
imgDoc.save()
# Get the watermark file just created
watermark = PdfFileReader(open(watermark_str, "rb"))
#Get our files ready
pdf1File = open('sample.pdf', 'rb')
page = PdfFileReader(pdf1File).getPage(0)
page.mergePage(watermark.getPage(0))
#Save the result
output.addPage(page)
output.write(file("output.pdf","wb"))
#The function which searches the current directory for image files.
def image_search():
found_images = []
for doc in os.listdir(os.curdir):
image_ext = ['.jpg', '.png', '.PNG', '.jpeg', '.JPG']
for ext in image_ext:
if doc.endswith(ext):
found_images.append(doc)
return found_images
main()
I also tried scaling and specifying the aspect ratio using the im_width variable, which gave the same output.
After a little bit of confusion about your goal I figured out that the goal is to make a PDF overview of the images in the current folder. To do so we actual don't need PyPDF2 as Reportlab offers everything we need for this.
See the code below with the comments as guidelines:
def main():
output_file_loc = "overview.pdf"
imgDoc = canvas.Canvas(output_file_loc)
imgDoc.setPageSize(A4) # This is actually the default page size
document_width, document_height = A4
images = image_search()
for image in images:
# Open the image file to get image dimensions
Image_file = Image.open(image)
image_width, image_height = Image_file.size
image_aspect = image_height / float(image_width)
# Determine the dimensions of the image in the overview
print_width = document_width
print_height = document_width * image_aspect
# Draw the image on the current page
# Note: As reportlab uses bottom left as (0,0) we need to determine the start position by subtracting the
# dimensions of the image from those of the document
imgDoc.drawImage(image, document_width - print_width, document_height - print_height, width=print_width,
height=print_height)
# Inform Reportlab that we want a new page
imgDoc.showPage()
# Save the document
imgDoc.save()
I am trying to convert a pdf to jpegs using wand, but when I iterate over the SingleImages in image.sequence and save each image separately. I am saving each image on AWS, with database references, using Django.
image_pdf = Image(blob=pdf_blob)
image_jpeg = image_pdf.convert('jpeg')
for img in image_jpeg.sequence:
memory_file = SimpleUploadedFile(
"{}.jpeg".format(img.page_number),
page.container.make_blob())
spam = Spam.objects.create(
page_image=memory_file,
caption="Spam")
This doesn't work, the page.container is calling the parent Image class, and the first page is written over and over again. How do I get the second frame/page for saveing?
Actually, you can get per-file blobs:
for img in image_jpeg.sequence:
img_page = Image(image=img)
Then you can work with each img_page variable like a full-fledged image: change format, resize, save, etc.
It seems you cannot get per file blobs without messing with c_types. So this is my solution
from path import path # wrapper for os.path
import re
import tempfile
image_pdf = Image(blob=pdf_blob)
image_jpeg = image_pdf.convert('jpeg')
temp_dir = path(tempfile.mkdtemp())
# set base file name (join)
image_jpeg.save(temp_dir / 'pdf_title.jpeg')
images = temp_dir.files()
sorted_images = sorted(
images,
key=lambda img_path: int(re.search(r'\d+', img_path.name).group())
)
for img in sorted_images:
with open(img, 'rb') as img_fd:
memory_file = SimpleUploadedFile(
img.name,
img_fd.read()
)
spam = Spam.objects.create(
page_image=memory_file,
caption="Spam Spam",
)
tempfile.rmtree(tempdir)
Not as clean as doing it all in memory, but it gets it done.
I am using PIL to resize an uploaded file using this method:
def resize_uploaded_image(buf):
imagefile = StringIO.StringIO(buf.read())
imageImage = Image.open(imagefile)
(width, height) = imageImage.size
(width, height) = scale_dimensions(width, height, longest_side=240)
resizedImage = imageImage.resize((width, height))
return resizedImage
I then use this method to get the resizedImage in my main view method:
image = request.FILES['avatar']
resizedImage = resize_uploaded_image(image)
content = django.core.files.File(resizedImage)
acc = Account.objects.get(account=request.user)
acc.avatar.save(image.name, content)
However, this gives me the 'read' error.
Trace:
Exception Type: AttributeError at /myapp/editAvatar Exception Value:
read
Any idea how to fix this? I have been at it for hours!
Thanks!
Nikunj
Here's how you can take a file-like object, manipulate it as an image in PIL, then turn it back into a file-like object:
def resize_uploaded_image(buf):
image = Image.open(buf)
(width, height) = image.size
(width, height) = scale_dimensions(width, height, longest_side=240)
resizedImage = image.resize((width, height))
# Turn back into file-like object
resizedImageFile = StringIO.StringIO()
resizedImage.save(resizedImageFile , 'PNG', optimize = True)
resizedImageFile.seek(0) # So that the next read starts at the beginning
return resizedImageFile
Note that there's already a handy thumbnail() method for PIL images. This is a variant of the thumbnail code I use in my own project:
def resize_uploaded_image(buf):
from cStringIO import StringIO
import Image
image = Image.open(buf)
maxSize = (240, 240)
resizedImage = image.thumbnail(maxSize, Image.ANTIALIAS)
# Turn back into file-like object
resizedImageFile = StringIO()
resizedImage.save(resizedImageFile , 'PNG', optimize = True)
resizedImageFile.seek(0) # So that the next read starts at the beginning
return resizedImageFile
It would be better for you to save the uploaded image and then display and resize it in template as you wish. This way you will be able to resize images at runtime. sorl-thumbnail is djano app which you can use for template image resizing, it is easy to use and you can use it in a view too. Here are examples for this app.
I'm trying to upload resized image to S3:
fp = urllib.urlopen('http:/example.com/test.png')
img = cStringIO.StringIO(fp.read())
im = Image.open(img)
im2 = im.resize((500, 100), Image.NEAREST)
AK = 'xx' # Access Key ID
SK = 'xx' # Secret Access Key
conn = S3Connection(AK,SK)
b = conn.get_bucket('example')
k = Key(b)
k.key = 'example.png'
k.set_contents_from_filename(im2)
but I get an error:
in set_contents_from_filename
fp = open(filename, 'rb')
TypeError: coercing to Unicode: need string or buffer, instance found
You need to convert your output image into a set of bytes before you can upload to s3. You can either write the image to a file then upload the file, or you can use a cStringIO object to avoid writing to disk as I've done here:
import boto
import cStringIO
import urllib
import Image
#Retrieve our source image from a URL
fp = urllib.urlopen('http://example.com/test.png')
#Load the URL data into an image
img = cStringIO.StringIO(fp.read())
im = Image.open(img)
#Resize the image
im2 = im.resize((500, 100), Image.NEAREST)
#NOTE, we're saving the image into a cStringIO object to avoid writing to disk
out_im2 = cStringIO.StringIO()
#You MUST specify the file type because there is no file name to discern it from
im2.save(out_im2, 'PNG')
#Now we connect to our s3 bucket and upload from memory
#credentials stored in environment AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
conn = boto.connect_s3()
#Connect to bucket and create key
b = conn.get_bucket('example')
k = b.new_key('example.png')
#Note we're setting contents from the in-memory string provided by cStringIO
k.set_contents_from_string(out_im2.getvalue())
My guess is that Key.set_contents_from_filename expects a single string argument, but you are passing in im2, which is some other object type as returned by Image.resize. I think you will need to write your resized image out to the filesystem as a name file and then pass that file name to k.set_contents_from_filename. Otherwise find another method in the Key class that can get the image contents from an in-memory construct (StringIO or some object instance).
print ("loading object", input_bucket, input_key)
response = s3client.get_object(Bucket=input_bucket, Key=input_key)
print("s3 get object response", response)
body = response['Body']
image = Image.open(body)
print ("generating thumbnail", output_width, output_height)
thumbnail = resizeimage.resize_thumbnail(
image, [output_width, output_height])
body.close()
print ("saving thumbnail", output_format)
with io.BytesIO() as output:
thumbnail.save(output, output_format)
print ("uploading thumbnail", output_bucket, output_key)
output.seek(0)
s3client.put_object(Bucket=output_bucket, Key=output_key,
Body=output, ContentType=output_content_type)