I am using a CodeJock ImageManager component to hold a variety of images. I want to put one of these images into a FlexGrid Cell.
The Images I have are Png format and have transparent backgrounds so when I load the image into the grid like so:
Grid.Cell(flexcpPicture, 123, 4) = _
ImageManagerControl.Icons.GetImage(ImageNum, 16).CreatePicture(xtpImageNormal)
the background which in the original image was transparent is now black:
(the same happens if I load the image into a PictureBox using the above method)
According to the documentation CreatePicture returns an StdPicture object, is there some way I can convert this image (using BitBlt perhaps) so that the black is white? I'm not sure if this even possible?
I only need to do this with about three images so if I have to load them into an ImageList or something else first that would be ok.
I'm not sure if this helps at all, but I've been playing around with the PictureBox. I put two picture boxes on a form, put a bmp file (this only works with bmp files, so it might not be helpful to you), and did this:
Picture2.PaintPicture Picture1.Picture, 0, 0, opcode:=vbNotSrcCopy
Which successfully inverted the bitmap. Here are the RasterOp constants: http://msdn.microsoft.com/en-us/library/aa243035(v=vs.60).aspx
Related
I do a LoadFromFile() for a PNG image into a Timage that is on a TPanel on a Form. The Form's OnCreate event maximizes the Form, and the Panel is set to alClient so it resizes nicely. But the PNG image does not, it only fills to the TPanel's design-time dimensions. And it looks horribly low resolution, no matter how hi-res the source image is.
I get it to resize in an OnClick event by using Image.SetBound(), but it does not look good.
I have also tried with a BMP and JPG, but without success.
I am guessing there is something fundamental I do not understand, but I cannot find the 'recipe' for this anywhere.
I am using Lazarus.
I have put 2 images on a form and synchronized their positions and sizes.
I can textout to both images, and after I made the ontop image transparent I can see the combined content of both images.
I can add further text to the bottom image and see it, but I can't see text I try to add to the transparent image.
I used the following code to make the top image transparent
image2.picture.Bitmap.TransparentColor:=clWhite;
image2.transparent:=true;
I guess I need to play with the image bitmap, but I can't find a solution that is not using other software.
Can someone help me with this please?
I am trying to add an image to a column on a TDbgrid that takes transparency into account. When drawing the image from a TImageList on the canvas in the DBGridDrawColumnCell procedure, I need the background of the image (the same color as the pixel in the lower left corner) to take on transparency. I want this transparency area to show the highlight color or non-highlight color, especially when themes are used, such as Aero. I have been able to accomplish this in older versions of Windows with color values of clHighlight or clWindow as the background color. But with Aero themes, it always paints a box behind the non-transparent part of the image instead of the gradient blue highlight color that Aero uses. How can I accomplish this?
I believe I am supposed to use alpha channel but I'm not sure how to do this from a TImageList to a canvas. I believe the cell is painted completely with the actual highlight color before I start drawing on the canvas in the cell. I just want to draw the non-transparency part of the image and leave the background.
I was able to finally determine how to display images on a dbgrid with transparency even if themes, such as Aero is used.
I used a regular TImageList and loaded the images that I needed to display on the dbgrid. In my case there were two and they were in icon (ico) format. Instead of transferring the image to a bitmap and then drawing it to the dbgrid canvas as most old code recommends, I simply used the following simple code in the DBGridDrawColumnCell procedure:
if DataCol=0 then
begin
if (MApptsConflict.Value='<none>') then
ImageIndex := 0
else
ImageIndex := 1;
ImageList.Draw(TDBGrid(Sender).Canvas,Rect.Left+2,Rect.Top+2,ImageIndex,True);
end;
This will draw directly to the dbgrid canvas from the TImageList which will give the desired transparency.
UPDATE: I tried it with bmp's loaded in the Timagelist and it worked too.
I am using PNG images as main image resource in my application. Since im using Delphi 7, i downloaded PNGImage lib and included it in project. I load images like this:
Form.image.Picture.LoadFromFile(PAnsiChar('\background.png'));
Image has transparent and semi transparent pixels on its border. The problem i get is that transparent pixels are filled with random zoomed part of my desktop with currently opened windows, while i expected to see what is actually located beneath form.
Additionally, form has this properties:
BorderStyle: bsNone;
TransparentColor: true;
Visible: false;
Here is a picture of current state (above black line) and desired:
Can this be fixed somehow or it is how delphi deals with transparency?
To have the form "shade" what's beneath it, use the forms AlphaBlend and AlphaBlendValue properties. The .png image doesn't have to be partially (alpha blended) transparent, but it can be.
If you want the form to be semi-transparent you use Alphablending, that's a limitation of Windows. In addition you can have a certain color fully transparent. In the following sample the forms color is clGray, which is also defined as the Transparent color property in addition to the Transparent property set to True. The image, aligned alClient, is 50% transparent, placed on a TImage which is set as transparent, but even so, it doesn't show up as semi-transparent unless you have AlphaBlending on. Again, this is a limitation of Windows. The best you can do is try with a fairly high value for AlphaBlendingValue (240..250) and a rather light image to find the right compromise.
In Mac OSX,
I have an image with black pixel in all 4 directions.
I want to programmatically crop the image to the maximum image rect.
Should i check for the black pixel and then create the crop rect or is there any supported API is there?
Create an NSImage of the desired size, lock focus on it, draw the desired crop rectangle of the source image into the whole bounds of the destination image, and unlock focus. The image you created now contains the crop from the source image.
Note that this will lose information like resolution (DPI), color profile, and EXIF tags. If you want to preserve those things (probably a good idea), use CGImage:
Use CGImageSource to load the image. Be sure to recover the properties of each image from the file, as well as the images themselves. And note that I used the plural: TIFF files can contain multiple images.
Use the CGImageCreateWithImageInRect function to crop out the desired section of each image. Don't forget to release each original image as appropriate.
If you want to write the cropped-out images to a file, do so using CGImageDestination. Pass both the images and the attributes dictionaries you obtained in step 1.