# Questions tagged [raster-image]

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### Image rotation using FFT

I'm not sure how practical this might be but is it possible to use Fast Fourier Transform to rotate a raster image? To be honest, I never really understood FFT, but I saw it being used for JPEG, for ...
• 1,459
158 views

### Is there a image-format that support an array per pixel?

For a project dealing with deep semantic labeling of images I need a format that supports arrays of arbitrary length for each pixel of the image. The array is an array of integers. Which image ...
• 61
2k views

### Draw angles lines in raster graphics using bresenham line algorithm

I at the moment trying to draw some angled lines using bresenham line algorithm which can circulate a 2d array of size 21x21, as a line angled from 0 - 2pi. So the idea is that the program has to ...
• 183
1k views

### Triangulated model rasterization: light-weight Python library

I have a 3D model, which consists of ~50 thousand vertices and 100 thousand triangles. Format is: there's array of vertices' coordinates and array of triangles, which has numbers of vertices (e.g., [1,...
• 161
2k views

### Image rotation algorithm

I would like to rotate a raster image by an arbitrary angle. I don't really care for speed: the rotation should be of highest quality possible. Could someone please suggest a suitable algorithm? I'm ...
• 1,459
740 views

### Wrong color in .ppm file

I'm going through the rasterizer tutorial from Scratchapixel, but I encountered a problem with the generation of the .ppm file. Since something was off, I reduced the example to the bare minimum, so I ...
564 views

### How is Raster and Random Scan Display different?

Raster scan display forms an image with pixel whereas a Random scan display works with Geometric primitives, but even a geometric primitve( a line) is made up of pixels so what is the difference?
61 views

### Compute angles and thereby endpoints in a raster grid?

I am at the moment having some issues with computing an endpoint in a raster grid that is also a valid position in a graph. I am trying to draw a line between these two points, but as the point I am ...
• 183
65 views

### Draw lines angled from 0 to 2 pi in a raster grid [duplicate]

I am trying to draw an angled line in a raster grid. The idea is to create a function that given a start point, a length and an angle, would give me the pixel positions that combined would give me a ...
• 31
349 views

### Image saved as DDS with 16f format in photoshop has strange FOURCC text

I am analyzing the hex code for DDS files which are compressed via Nvidia's dds plugin in photoshop. I noticed something strange when having a 16 bit float file. This is the dialog: When I look at ...
• 123
62 views

### Normalization technique to increase spread of data in rgb space

I am visualizing a dataset. My technique is to encode the data into a rgb image with the channel range [0, 255]. The data clusters in a narrow range relative to [0, 255], however, so I'm not getting ...
• 121
1 vote
317 views

### How to use maximum resolution (pixel density) with OpenGL in MS Windows

CodeBlocks offers an example program in C, that uses OpenGL. It draws a single multicoloured rotating triangle. I have been building on this example. I am a novice in C and in OpenGL. I believe that I ...
• 183
1 vote
828 views

### How to calculate spatial frequency of an image just in one direction?

FFT spectra is not what is needed; what I need is a histogram showing which frequencies are there in image in horizontal direction, and which one is dominant Such spatial frequency is usually known ...
• 111
1 vote
836 views

### How to generate the stereographic projection of a 3D model

Given a 3D model, is there a way to stereographically project it to a 2D image? In particular, I would only need a little more than half the model (the lower half) to be mapped to the plane (mapping ...
1 vote
286 views

### Deskewing and Cropping Scans using ImageMagick

Attempting to deskew and crop scans of a CD booklet using ImageMagick. Here's one image which I've been using as an example on which to build my one-liner - https://mega.nz/#!jIQD3aqC!PbjG4_Xaq-...
• 11
431 views

### Screen Space anti aliasing?

I have the following challenge. I am given a black and white image with rasterized lines. Given this input, I want to extend the edges to cover more than one pixel and antialias the edges. My first ...
• 1,706
85 views

### How to identify images with similar content?

There's a set of pictures that if you take them literally, they're different. That is, there can be two images of the same thing among them, only in different hue. In addition, among these two, there ...
120 views

### Is it possible to convert Polar to Cartesian coordinates and map result to an image using opengl?

Is it possible to convert Polar to Cartesian coordinates and map result to an image? I want to get the output same as the distort depolar 0 from image magick. https:...
• 101
24 views

### Animated bitmaps with 2 colours only

I want to create an animated GIF, but instead of 8-bit 256 colours, my data is comprised of binary bitmaps of black/white pixels. Can GIF accommodate this, or are pixels in GIF always 8-bit indices? I ...
• 270
42 views

### How to render a rotated raster image with lesser aliasing

I am wondering about techniques for rendering a rotated and or scaled raster image. Currently I use the following algorithm Render everything at double resolution and store the result in ...
• 101
Say we have a image reconstruction filter $h:R\to\mathbb R$ defined on the raster space $[0,w]\times[0,h]$, where $w,h\in\mathbb N$ define the width and height of the image plane in pixels, ...