Free hand cropping an image
1 visualización (últimos 30 días)
Mostrar comentarios más antiguos
Jane
el 23 de Nov. de 2013
Comentada: Image Analyst
el 22 de Jul. de 2020
Hello all,
I saw this post recently on this forum by Sean de Wolski on 19 Jun 2013. This is to free hand crop an image and blackout the rest. However, I'm using a jpg and it's causing the rest of my image to have a blueish tint. Do you know how to fix this? Thanks in advance!!
I = imread('cameraman.tif');
imshow(I);
h = imfreehand; %draw something
M = ~h.createMask();
I(M) = 0;
imshow(I);
2 comentarios
Image Analyst
el 25 de Mayo de 2017
h.createMask() creates a binary image mask that is true/1/white inside the drawn area and false/0/black outside the drawn area. Using ~ inverts that mask so it's black inside the drawn area and white outside.
Respuesta aceptada
Image Analyst
el 23 de Nov. de 2013
Don't use jpg images. I never do. They are not suitable for doing image analysis. Use PNG format because it's lossless compression.
I used your code and did not get a bluish tint.
3 comentarios
Mathews Jabaraj Soloman
el 21 de Jul. de 2020
Editada: Mathews Jabaraj Soloman
el 21 de Jul. de 2020
I am using an ultrasound image with .png extension. While using the above code I am getting the bluish color other than the ROI drawn both using 'imfreehand' and 'drawfreehand'. And my image has the size of "899x1442x3". It has 3 channel, does it has to do something with the bluish color of the background.
looking forward for answers.
Image Analyst
el 22 de Jul. de 2020
I don't know what that means. Why would an ultrasound image, which is grayscale, have a bluish color. You forgot to post your image, and your code. Start a new thread with those and tell us there (not here) what region of the image you're outlining, and if "getting the bluish color" means that you are outlining the blue region, or somehow you get a bluish tint to the image after you do the outlining.
Más respuestas (0)
Ver también
Categorías
Más información sobre Convert Image Type en Help Center y File Exchange.
Productos
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!