there are a ton of scaling instructions for GIMP but all of them tell you to scale and save easy peasy. I feel like I'm taking crazy pills.
This is what my save or export generates:
How can I simply export a selection? Shouldn't the GIMP instructions include this detail? Sorry for ranting.
In Gimp (and some other popular image editors) the image you work on is actually made of separate images (a.ka.a layers) held together on a "canvas". The "canvas" gives the size of the final image.
There are three different ways to scale things and you have to use the right one:
The Scale tool : scales the active layer by dragging corners. Doesn't change the size of the canvas. This is probably what you used.
Layer>Scale layer: scales the active layer by providing explicit dimensions. Doesn't change the size of the canvas.
Image>Scale image: scales the whole image contents and the canvas. This is probably what you should have used.
What happened to give you the image above is that you resized the layer using the Scale tool, so you got a tiny image in the corner of the canvas, which didn't change size. The uncovered part of the canvas was displayed as a checkerboard pattern. If you exported to a format that supports transparency such as PNG or GIF the image would have been transparent, but since you exported to JPG which doesn't support transparent images Gimp replaced the transparent part by the default background color.
Everything is well explained on their website. https://www.gimp.org/tutorials/GIMP_Quickies/
Related
In mobile view mapbox renders black image instead of raster image. I suspect this is because of the size of image(3.9 MB), also this is happening mostly on chrome browser for mobile. Please help me find the potential issue here?
This sounds as if you could be running into the No-Data issue, when rendering transparency.
The black background that appears is the part of the raster image that does not contain any data. Generally a raster image is a rectangular grid of pixels. When you are working with data that is not rectangular, there are pixels within the grid that don't contain any data. These pixels are expressed as NoData values and represent the absence of data. GeoTIFFs that are uploaded to Mapbox Studio are displayed as JPEG to save space and make maps load quickly. Since JPEG cannot display transparency, NoData values appear black.
Please see this documentation on how to resolve this:
https://docs.mapbox.com/help/troubleshooting/raster-transparency-issues/#why-black-backgrounds-appear
I keep getting black bars on the sides and occasionally on the top and bottom as well. I've been troubleshooting the issue for at least 4 days to no avail. I tried, cropping on export pane, different settings/aspect ratios, new sequences with different settings and Scale to Fit/Fill.
The only settings that got rid of the black bars was changing the pixel ratio to 1.0 but that made my video very blurry.
My sequence settings are same FPS 1920/1080 with matching pixel ratio of 1.0 (to the imported clips). And original clips are all 1920/1080 I don't know what their pixel ratio is but when I import them to Premiere they are all 1.0
These are the export settings
https://i.gyazo.com/af4d2459228bfaad5d86864cb1263aa3.png
From the looks of your title I'm going to assume you're uploading to YouTube? If that's so, you might try using one of the 'Presets' other than custom. If you scroll all the way down, in the preset dropdown, I remember there being options to optimise for YouTube 240/480/720/1080 and so on. This might change what you need to change.
Alternatively, I've made the mistake before of aligning my clips to the 'focus lines' rather than to the edge of the screen. Your solution may be as simple as transforming your clips bigger.
I know this is pretty late to the party. I hope you found what you were looking for.
I have an ximage which I want to zoom in on, and display. I'm currently taking the naive approach:
allocate bigger image
use nearest-neighbor interpolation to fill it in.
put the whole image on a pixmap.
Which works, but slowly, and crawls once I approach bigger zoom levels, like 800%. The gimp, however, can zoom in to 3200% and still feel snappy. What's the approach taken here? Should I only fill one screen at a time? But then what about scrolling: wouldn't performing interpolation, and an XPutImage, and an XCopyArea on each expose kill performance?
I'm not expert in Xlib, but in my opinion a good approach would be to draw only the zoomed part, instead of computing the interpolation of the entire image.
For scrolling, if you are looking for performances, you may copy the part of the old zoom which is still visible in the new position, and compute the interpolation of the "discovered" pixels. For example, when scrolling down, you may copy the bottom of the previous image and paste it higher, and then compute/draw the new visible stuff at the bottom.
Most modern X11 applications don't use Xlib directly much, if at all. My guess would be that Gimp is rendering the zoomed image into a buffer itself and drawing that to the window, rather than working with the image in an XImage.
I'm working on SEM image processing application, written in WPF. I have an image display control, derived from Canvas, which displays image & overlays using DrawingVisuals (one for each "layer"). It also implements Zoom & Pan using scale & translate transform, applied on DrawingVisuals.
When I zoom in the image to see individual pixels, they are displayed smooth, evidently using bilinear filtering to stretch the bitmap (no surprise, as WPF is rendered through Direct3D). However, for my use case, I would rather see individual pixels as sharp boxes, as usual in any image editor like Photoshop. That's why user of my app zooms the image -> to be able to operate on pixel level.
Is there such option in WPF (other than manually stretching the bitmap before displaying it)? I was not able to find anything.
thanks in advance,
Zbynek Vrastil
Czech Republic
Finally found an answer, with some help from Experts Exchange. Class RenderOptions defines attached property BitmapScalingMode, which can be set to NearestNeighbor. So,
RenderOptions.SetBitmapScalingMode(imageDisplay, BitmapScalingMode.NearestNeighbor);
does the trick.
Zbynek Vrastil
Hate to put a dampener on things, but if NearestNeighbor works like GDI+, then this will give you a limited success. As you increase magnification in areas of high contrast you might not get the desired results. In GDI+ you find blacks becoming blue, and whites becoming red - again I stress in areas of high contrast! If this isn't the case in WPF, think yourself lucky!
Perhaps a WCF developer could confirm that?
I've found that there are more options to consider, but I can only speak for the GDI+ Graphics class, which might be useful to someone.
Graphics graph = e.Graphics;
graph.InterpolationMode = InterpolationMode.NearestNeighbor;
graph.CompositingQuality = CompositingQuality.AssumeLinear;
graph.SmoothingMode = SmoothingMode.None;
This works for me. I think the SmoothingMode is the trick. Hope this helps someone else out there.
What I would like to do is the following:
Change the points of the four corners of an image.
What is possible now, is to change the top left corner. But that will only move the image.
I want to transform the image by changing the corner coordinates.
The effect will be a 3d-kind transformation.
A skew transformation will not do, I want to be able to position the corners freely.
Is this possible?
I don't think you can just place corners of an image arbitarily and have it distort accordingly. It might be better if you specified the effect you are trying to acheive.
There are couple of options which may or may not suit.
Would a Matrix3DProjection serve your purpose (as well as do a lot a math for you)?
Would using the image to Fill a path or using a path to clip the image get the effect you want.