I am using gdcm ImageReader to read multiframe dicom file. It reads multiframe correctly but I am unable to display the multiframe dicom file.
I am using vtkImageViewer to display single frame image,
vtkImageViewer viewer = new vtkImageViewer();
vtkDICOMImageReader reader = new vtkDICOMImageReader();
reader.SetInputfile(..\\inputFile);
viewer.SetInput(reader.GetOutput());
It displays single frame images correctly but does not display multiframe images.
Anybody knows how to display multiframe dicom files???
I would advise you to use vtkImageViewer2 instead of vtkImageViewer in this context. The former has a method, SetSlice, where, according to the documentation:
'Each call to SetSlice() changes the image data (slice) displayed AND changes the depth of the displayed slice in the 3D scene'
Example**:
vtkSmartPointer<vtkImageViewer2> imageViewer = vtkSmartPointer<vtkImageViewer2>::New();
imageViewer->SetSlice(5); //Specify the index/slice in image data
** Assumes you have set the input connection/data, example in c++ language.
Related
I want to decode and understand the structure of various latest image formats (namely WebP, JPEG XL, HEIF and AVIF) and compare header information with respect to image data to see which format is header information heavy with respect to image data. I was wondering how I can do this using Python.
Is there a simple way to decode various image file formats of the same image in either HEX or Binary and learn how much of the file contents is the image data and how much else is the header information? Better yet, is there a way to learn the breakdown of header information for various file formats??
So far I got to a point where I got a file to open in binary mode (Below is the sample code I have for the AVIF test image) but I'm not sure how I can decrypt, read and understand the structure. Googling around, I found some information for JPEG format (like the information shown on this page for JPEG https://yasoob.me/posts/understanding-and-writing-jpeg-decoder-in-python/) but none for WebP, HEIF, and AVIF on how I can read the binary format.
image = 'test.avif'
with open(image, 'rb') as image_file:
content = image_file.read()
Content
I wish to know how exactly can we extract the header information from the images while compression.
I'm reading a tiff file using OpenSlide. Due to its large size, I'm planning to read the image by regions of 4k x 4k using read_region() function. After getting that region, I want to do the same process I have planned for the complete tiff file. To continue that process, I need the image read in OpenSlide. So I can use OpenSlide parameters.
I tried to read the selected region using read_region with Openslide again as follows.
wsi = wsi.read_region((0,0),0,(4000,4000))
wsi = openslide.OpenSlide(wsi)
The issue was I could use parameters I usually get when reading a tiff file using OpenSlide. Does anyone know a way to solve this issue?
I want to add a SVG image to PdfSignatureAppearance. The method setSignatureGraphic has an ImageData parameter now in iText7. I couldn't find a way to create an imageData from SVG because ImageDataFactory is not supporting this format.
Can you please guide me on how to do that?
Note that with iText5 I was able to add svg after converting it to PDF and import it to a PDFTemplate then create an image after instantiate the PDFTemplate. setSignatureGraphic was accepting com.itextpdf.text.Image as parameter
Your question could be split into 2 more precise and simple ones:
How to process an SVG with iText?
How to create an ImageData instance out of the result of point 1?
As for question 1: one can use SvgConverter class (part of iTextCore's svg module). Unfortunately there are only PDF-related methods there: an SVG could be converted either to Image (class of layout module), or to PdfFormXObject (again PDF-related) or to a PDF file.
// to PDF
SvgConverter.convertToImage(new FileInputStream(sourceFolder + "your_svg.svg"), signer.getDocument()); // the mentioned `signer` is the instance of PdfSigner which you use to sign the document
// to Image
SvgConverter.convertToImage(new FileInputStream(sourceFolder + "your_svg.svg"), new File(destinationFolder + "svgAsPdf.pdf"));
As for question 2, there are several answers:
a) Suppose that you want to use this Image as the PdfSignatureAppearance's graphics data. For now the class doesn't provide a convenient setter, however, you could use some low level methods - either getLayer0 or getLayer2 to get the signature's background or foreground. They are represented by PDfFormXObject, hence you can use Canvas to add your image to them:
Image svg = SvgConverter.convertToImage(new FileInputStream(sourceFolder + "your_svg.svg"), signer.getDocument());
Canvas canvas = new Canvas(appearance.getLayer0(), signer.getDocument());
canvas.add(svg);
canvas.close();
b) Suppose that your goal is to use the rendered bitmap as the PdfSignatureAppearance's graphics data. Then there is a specific iText product - pdfRender - which converts PDF files to images. The following code could be applied:
PdfToImageRenderer.renderPdf(new File(destinationFolder + "svgAsPdf.pdf"), new File(folderForTheResultantImage));
Now you can create an ImageData instance out of the resultant image file (by default a PDF is converted to a series of images with the format "pdfnamePAGE_NUMBER.jpg", but one could customize either the name or the output image format). In your case the PDF consist of just one page (which represents the converted SVG) and its name is "image1.jpg". The rest is obvious:
appearance.setSignatureGraphic(ImageDataFactory.create(destinationFolder + "image1.jpg"));
I'm getting some unwanted rotation when loading images using PIL. I'm loading image samples and their binary mask, so this is causing issues. I'm attempting to convert the code to use openCV instead, but this is proving sticky. I haven't seen any arguments in the documentation under Image.load(), but I'm hoping there's a workaround I just haven't found...
There is, but I haven't written it all up. Basically, if you load an image with EXIF "Orientation" field set, you can get that parameter.
First, a quick test using this image from the PIL GitHub source Pillow-7.1.2/Tests/images/hopper_orientation_6.jpg and run jhead on it you can see the EXIF orientation is 6:
jhead /Users/mark/StackOverflow/PillowBuild/Pillow-7.1.2/Tests/images/hopper_orientation_6.jpg
File name : /Users/mark/StackOverflow/PillowBuild/Pillow-7.1.2/Tests/images/hopper_orientation_6.jpg
File size : 4951 bytes
File date : 2020:04:24 14:00:09
Resolution : 128 x 128
Orientation : rotate 90 <--- see here
JPEG Quality : 75
Now do that in PIL:
from PIL import Image
# Load that image
im = Image.open('/Users/mark/StackOverflow/PillowBuild/Pillow-7.1.2/Tests/images/hopper_orientation_6.jpg')
# Get all EXIF data
e = im.getexif()
# Specifically get orientation
e.get(0x0112)
# prints 6
Now click on the source and you can work out how your image has been rotated and undo it.
Or, you could be completely unprofessional ;-) and create a function called SneakilyRemoveOrientationWhileNooneIsLooking(filename) and shell out (subprocess) to exiftool and remove the orientation with:
exiftool -Orientation= image.jpg
Author's "much simpler solution" detailed in above comment is misleading so I just wanna clear that up.
Pillow does not automatically apply EXIF orientation transformation when reading an image. However, it has a method to do so: PIL.ImageOps.exif_transpose(image)
OpenCV automatically applies EXIF orientation when reading an image. You can disable this behavior by using the IMREAD_IGNORE_ORIENTATION flag.
I believe the author's true intention was to apply the EXIF orientation rather than ignore it, which is exactly what his solution accomplished.
I'm trying to read a DICOM image with ITK reader then convert it into vtkimagedata for rendering.
As I convert ITK image with "itk::ImageToVTKImageFilter" and render it in vtkrenderwindow, the origin of this volume is set at center of this volume. How can I do to set the coordinate of render window same to the DICOM image?
Here's my code:
vtkSmartPointer<vtkImageData> vtkImg = ITKconnectVTK(itkImg);
vtkSmartPointer<vtkImageData> ITKconnectVTK(ImageType::Pointer inputImg)
{
ConnectorType::Pointer connector = ConnectorType::New();
connector->SetInput(inputImg);
connector->Update();
return connector->GetOutput();
}
Here is an example which does just that:
https://itk.org/Wiki/VTK/ExamplesBoneYard/Cxx/VolumeRendering/itkVtkImageConvert
And another one which does not need an image:
https://itk.org/Wiki/ITK/Examples/WishList/IO/itkVtkImageConvertDICOM
You can read the direct dicom series in the VTK, and if you need some filter send the image to itk and then get it again.
reading with vtk:
https://www.vtk.org/Wiki/VTK/Examples/Cxx/IO/ReadDICOM
convert from itk to vtk:
https://itk.org/Wiki/ITK/Examples/IO/ImageToVTKImageFilter
convert from vtk to itk
https://itk.org/Wiki/ITK/Examples/Broken/Images/VTKImageToImageFilter
you need to enable itkvtkglue in itk for this.