Questions tagged [raster-image]
The raster-image tag has no usage guidance.
21
questions
7
votes
2
answers
4k
views
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
6
votes
2
answers
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
5
votes
1
answer
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
4
votes
1
answer
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
3
votes
1
answer
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
3
votes
1
answer
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 ...
- 45
3
votes
2
answers
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?
3
votes
0
answers
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
3
votes
0
answers
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
2
votes
1
answer
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
2
votes
0
answers
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
1
answer
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
1
answer
827
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
2
answers
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 ...
- 111
1
vote
0
answers
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
0
votes
1
answer
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
0
votes
1
answer
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 ...
0
votes
1
answer
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
0
votes
0
answers
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
0
votes
0
answers
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
0
votes
0
answers
64
views
How is the image reconstruction filter on the path space defined in terms of the filter on the raster space?
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, ...
- 203