The problem is that I can’t understand how the “official” JPG->PGM convertitors work in terms of what value to assign to the final pixel (i guess, 0->255) starting from the classic RGB format. There is likely a gamma adjustment in the conversion those “official” tools are using.That is, it is not just a linear transform. … Read more
EDIT: I wrote a Python script for this. As your objective is blurring (for privacy protection), you basically need a high recall detector as a first step. Here’s how to go about doing this. The included code hints use OpenCV with Python. Convert to Grayscale. Apply Gaussian Blur. img = cv2.imread(‘input.jpg’,1) img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) … Read more
I have a requirement where in I have to determine whether a photo is corrupted and accordingly tag it as such. You can try some things, but with certain file formats (example: BMP, JPEG to some extent) only a human can ultimately decide if the file is OK or corrupted. The simplest test is to … Read more
The technique is called texture mapping. This is a code example from surface function (R2011b): load clown surface(peaks,flipud(X),… ‘FaceColor’,’texturemap’,… ‘EdgeColor’,’none’,… ‘CDataMapping’,’direct’) colormap(map) view(-35,45) This example loads RGB image from “peppers.png” and maps it onto cylinder: imgRGB = imread(‘peppers.png’); [imgInd,map] = rgb2ind(imgRGB,256); [imgIndRows,imgIndCols] = size(imgInd); [X,Y,Z] = cylinder(imgIndRows,imgIndCols); surface(X,Y,Z,flipud(imgInd),… ‘FaceColor’,’texturemap’,… ‘EdgeColor’,’none’,… ‘CDataMapping’,’direct’) colormap(map) view(-35,45) Things are … Read more
here’s an alternative: Create the 2D-Gaussian: function f=gaussian2d(N,sigma) % N is grid size, sigma speaks for itself [x y]=meshgrid(round(-N/2):round(N/2), round(-N/2):round(N/2)); f=exp(-x.^2/(2*sigma^2)-y.^2/(2*sigma^2)); f=f./sum(f(:)); Filtered image, given your image is called Im: filtered_signal=conv2(Im,gaussian2d(N,sig),’same’); Here’s some plots: imagesc(gaussian2d(7,2.5)) Im=rand(100);subplot(1,2,1);imagesc(Im) subplot(1,2,2);imagesc(conv2(Im,gaussian2d(7,2.5),’same’));
What you get is just the toString output of an array. You need however the byte array converted to a String. You should create a method in bean public String getByteArrayString() { return new String(this.imageByteArray); } and reference this in your JSP. While technically you should define which encoding to use for an array of … Read more
The reason your new image is bigger than your original is because the SAVEAS function saves the entire figure window, not just the contents of the axes (which is where your image is displayed). Your question is very similar to another SO question, so I’ll first point out the two primary options encompassed by those … Read more
It is not clear exactly what you are trying to do. If you are talking about JavaFX 2.0, the following code works. If you are loading a lot of images and need to conserve memory, you only have to create enough ImageView’s for the number you want to display at one time. Then as you … Read more
For the fun of it, I wrote an ImageGrid component for you. It has only a vertical scroll bar; resizing the width of the control adjusts the column count and row count. The images are cached as resized bitmaps in an internal list, along with their file names. Because loading and resampling these images may … Read more
It is absolutely possible without doing anything extra. Hadoop provides us the facility to read/write binary files. So, practically anything which can be converted into bytes can be stored into HDFS(images, videos etc). To do that Hadoop provides something called as SequenceFiles. SequenceFile is a flat file consisting of binary key/value pairs. The SequenceFile provides … Read more